Maturation and development of fetal pig intestinal tissue in immunodeficient mice

Purpose: This study aimed to compare the degree of maturation and development of fetal pig segmental intestinal tissue with that of spheroids created by in-vitro reaggregation of dissociated fetal intestinal cells after transplantation into immunodeficient mice. Methods: Fetal pig small intestines were transplanted as segmental grafts into the omentum and subrenal capsules of immunodeficient mice or enzymatically treated to generate single cells. Spheroids made by in-vitro reaggregation of these cells were transplanted into the subrenal capsules of immunodeficient mice. The segmental grafts and spheroids were harvested four and eight weeks after transplantation, and the structural maturity and in-vivo development of these specimens were histologically evaluated. Results: The spheroids were engrafted and supplied blood vessels from the host mice, but an intestinal layered structure was not clearly observed, and there was almost no change in size. On the other hand, the segmental grafts formed deep crypts in the mucus membrane, the inner circular layer, and outer longitudinal muscles. The crypts of the transplanted grafts harvested at eight weeks were much deeper, and the smooth muscle layer and the enteric nervous system were more mature than those of grafts harvested at the fourth week, although the intestinal peristaltic wave was not observed. Conclusions: Spheroids created from fetal small intestinal cells could not form layered structures or mature sufficiently. Conversely, segmental tissues structurally matured and developed after in-vivo transplantation and are therefore potential grafts for transplantation.

[Transplantation cardiaque pédiatrique : quel futur ?] / The future of pediatric heart transplantation.

The future of pediatric heart transplantation. Pediatric heart transplantation developed in the 1980s, following the introduction of cyclosporine. The International Registry includes more than 14 000 patients (10 % of the whole). The results improved progressively. However, two drawbacks persist : a shortage of donors, particularly in infants and a high morbi-mortality on the long term. The rapid achievement of a pediatric artificial heart is unlikely. The future offers two directions. Firsly xenotransplantation : the production of genetically-modified pigs and new immuno-suppressive modalities allow long-term survival in heterologous pig/primate transplantation. Human clinical trials may begin soon, particularly in neonates. Secondly tissue engineering : constant advances (scaffolds, cells lines, growth factors) may make possible the production of a functional heart from the receivor's own stem-cells.

Transplantation cardiaque pédiatrique : quel futur ? La transplantation cardiaque pédiatrique s'est développée dans les années 1980, avec l'avènement de la ciclosporine. Le Registre International compte plus de 14 000patients (10 % de l'ensemble). Les résultats se sont progressivement améliorés, mais deux écueils persistent : la pénurie de donneurs, en particulier chez le nourrisson, et la morbi-mortalité élevée à très long terme. Le développement rapide d'un coeur artificiel adapté à l'enfant est peu probable et l'avenir s'oriente dans deux directions. D'une part la xénotransplan¬tation, la production de porcs génétiquement modifiés et des trai¬tements immunosuppresseurs innovants ayant permis la survie prolongée de greffons cardiaques entre porc et primate. Les essais cliniques semblent proches, en particulier chez le nouveau-né. D'autre part l'ingénierie tissulaire ; en effet des progrès constants (matrices, lignées cellulaires, facteurs de croissance) laissent en¬trevoir la possibilité de créer un coeur fonctionnel à partir des propres cellules du receveur.

Differentiation of Microencapsulated Neonatal Porcine Pancreatic Cell Clusters in Vitro Improves Transplant Efficacy in Type 1 Diabetes Mellitus Mice.

BACKGROUND: Neonatal porcine pancreatic cell clusters (NPCCs) have been proposed as an alternative source of ß cells for islet transplantation because of their low cost and growth potential after transplantation. However, the delayed glucose lowering effect due to the immaturity of NPCCs and immunologic rejection remain as a barrier to NPCC's clinical application. Here, we demonstrate accelerated differentiation and immune-tolerant NPCCs by in vitro chemical treatment and microencapsulation. METHODS: NPCCs isolated from 3-day-old piglets were cultured in F-10 media and then microencapsulated with alginate on day 5. Differentiation of NPCCs is facilitated by media supplemented with activin receptor-like kinase 5 inhibitor II, triiodothyronine and exendin-4 for 2 weeks. Marginal number of microencapsulated NPCCs to cure diabetes with and without differentiation were transplanted into diabetic mice and observed for 8 weeks. RESULTS: The proportion of insulin-positive cells and insulin mRNA levels of NPCCs were significantly increased in vitro in the differentiated group compared with the undifferentiated group. Blood glucose levels decreased eventually after transplantation of microencapsulated NPCCs in diabetic mice and normalized after 7 weeks in the differentiated group. In addition, the differentiated group showed nearly normal glucose tolerance at 8 weeks after transplantation. In contrast, neither blood glucose levels nor glucose tolerance were improved in the undifferentiated group. Retrieved graft in the differentiated group showed greater insulin response to high glucose compared with the undifferentiated group. CONCLUSION: in vitro differentiation of microencapsulated immature NPCCs increased the proportion of insulin-positive cells and improved transplant efficacy in diabetic mice without immune rejection.

Modified posterior tibialis muscle transfer for treatment of foot drop and varus deformity after common peroneal nerve injury / 中华创伤杂志

Objective:To investigate the early effect of modified posterior tibialis muscle transfer in treating foot drop and varus deformity caused by common peroneal nerve injury.Methods:A retrospective case series study was conducted to analyze the clinical data of 6 patients with foot drop of common peroneal nerve palsy and varus deformity admitted to Beijing Jishuitan Hospital from December 2017 to October 2019, including 4 males and 2 females, aged 33-48 years [(39.5±6.0)years]. The left side was involved in 4 patients and the right side in 2 patients. All patients underwent posterior tibial muscle transfer. The insertion of posterior tibial muscle was reconstructed in the fourth metatarsal with the tendon allograft to correct foot drop and varus deformity. The range of motion of active ankle dorsiflexion and plantar flexion and range of motion of varus and valgus of foot were measured before operation and at the last follow-up. The isokinetic torque peak value of ankle dorsiflexion and plantar flexion at 60°/s angular velocity and peak isokinetic torque of foot varus and valgus at 60°/s angular velocity were measured before operation and at the last follow-up. The postoperative foot imaging evaluation was performed at the last follow-up, including Meary angle, calcaneal projection and diameter of the fourth metatarsal. The American Orthopaedic Foot & Ankle Association (AOFAS) ankle-hindfoot score was used to evaluate the ankle function.Results:All patients were followed up for 6-17 months [10(6, 15)months]. At the last follow-up, the range of motion of dorsiflexion of the ankle [6(0, 10)°] and foot valgus [3(0, 5)°] were significantly improved compared with the preoperative level [-31(-33, -28)°, -10(-12, -8)°] ( P<0.05); the ankle dorsiflexion torque [(7.7±0.8)Nm] and foot valgus torque [(7.2±0.7)Nm] were significantly improved compared with the preoperative level [(0.0±0.0)Nm, (2.1±0.6)Nm]at 60°/s angular velocity ( P<0.01). Imaging examination showed no acquired flat foot deformity and deformation of the fourth metatarsal insertion. The AOFAS ankle-hindfoot score increased from 50-73 points [(61.3±8.4)points] before operation to 75-97 points [(86.8±7.2)points] at the last follow-up ( P<0.01). Conclusion:For foot drop and varus caused by common peroneal nerve injury, modified posterior tibialis muscle transfer can increase the torque of ankle dorsiflexion and valgus, improve the ankle range of motion, and accelerate the ankle function recovery.

Progress Toward Cardiac Xenotransplantation.

Consistent survival of life-supporting pig heart xenograft recipients beyond 90 days was recently reported using genetically modified pigs and a clinically applicable drug treatment regimen. If this remarkable achievement proves reproducible, published benchmarks for clinical translation of cardiac xenografts appear to be within reach. Key mechanistic insights are summarized here that informed recent pig design and therapeutic choices, which together appear likely to enable early clinical translation.

Surgical Options for Aortic Root Replacement in Destructive Endocarditis.

OBJECTIVE: To analyze patients' preoperative characteristics, surgical data, postoperative courses, and short- and long-term outcomes after implantation of different full-root prostheses for destructive aortic valve endocarditis. METHODS: Between 1999 and 2018, 80 patients underwent aortic root replacement due to infective endocarditis in our institution. We analyzed the abovementioned data with standard statistical methods. RESULTS: The Freestyle stentless porcine prostheses were implanted in 53 (66.25%) patients, biological valve conduits in 13 (16.25%), aortic root homografts in nine (11.25%), and mechanical valve conduits in five (6.25%). There were no significant preoperative differences between the groups. The incidence of postoperative complications and intensive care unit length of stay did not differ significantly between the groups. The 30-day mortality rate was low among Freestyle patients (n=8, 15.1%) and high in the mechanical conduit cohort (n=3, 60%), though with borderline statistical significance (P=0.055). The best mean survival rates were observed after homograft (13.7 years) and stentless prosthesis (8.1 years) implantation, followed by biological (2.8 years) and mechanical (1.4 years) conduits (P=0.014). The incidence of reoperations was low in the mechanical conduit group (0) and stentless bioroot group (n=1, 1.9%), but two (15.4%) patients with biological conduits and three (33.3%) patients with homografts required reoperations in the investigated follow-up period (P=0.005). CONCLUSION: In patients with the destructive form of aortic valve endocarditis, homografts and stentless porcine xenografts offer better survival rates than stented valve conduits; however, the reoperation rate among patients who received homograft valves is high.

Surgical options for aortic root replacement in destructive endocarditis

Abstract Objective: To analyze patients' preoperative characteristics, surgical data, postoperative courses, and short- and long-term outcomes after implantation of different full-root prostheses for destructive aortic valve endocarditis. Methods: Between 1999 and 2018, 80 patients underwent aortic root replacement due to infective endocarditis in our institution. We analyzed the abovementioned data with standard statistical methods. Results: The Freestyle stentless porcine prostheses were implanted in 53 (66.25%) patients, biological valve conduits in 13 (16.25%), aortic root homografts in nine (11.25%), and mechanical valve conduits in five (6.25%). There were no significant preoperative differences between the groups. The incidence of postoperative complications and intensive care unit length of stay did not differ significantly between the groups. The 30-day mortality rate was low among Freestyle patients (n=8, 15.1%) and high in the mechanical conduit cohort (n=3, 60%), though with borderline statistical significance (P=0.055). The best mean survival rates were observed after homograft (13.7 years) and stentless prosthesis (8.1 years) implantation, followed by biological (2.8 years) and mechanical (1.4 years) conduits (P=0.014). The incidence of reoperations was low in the mechanical conduit group (0) and stentless bioroot group (n=1, 1.9%), but two (15.4%) patients with biological conduits and three (33.3%) patients with homografts required reoperations in the investigated follow-up period (P=0.005). Conclusion: In patients with the destructive form of aortic valve endocarditis, homografts and stentless porcine xenografts offer better survival rates than stented valve conduits; however, the reoperation rate among patients who received homograft valves is high.

[Acellular xenogenic dermal matrix as a spacer graft for treatment of eyelid retraction related to thyroid associated ophthalmopathy].

Objective: To evaluate the efficacy and safety of an acellular xenogenic dermal matrix (AXDM) as a spacer graft in the surgery to treat upper and/or lower eyelid retraction (UER/LER) in patients with thyroid associated ophthalmopathy (TAO). Methods: This was a retrospective case series study. From January 2016 to December 2017, all the TAO patients who underwent the eyelid retraction surgery with an AXDM as a spacer graft in Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine were included in the study. The follow-up duration was at least 6 months. Eyelid height, ocular discomfort symptoms, and complications were recorded and used to evaluate the efficacy and safety. The treatment outcomes were divided into good, acceptable and unacceptable outcomes. Nonparametric test was used to compare the efficacy of upper and lower eyelid surgery. Results: Eighty patients (102 eyes) were included, consisting of 43 patients (56 eyes) with UER and 37 patients (46 eyes) with LER. The UER patients included 34 females (median age, 37 years) and 9 males (median age, 47 years). The LER patients included 20 females (median age, 39 years) and 17 males (median age, 40 years). At 6 months after surgery, ocular discomfort was relieved in 79.0% (64/81) eyes; photophobia was relieved in 69.5% (41/59) eyes; tearing was relieved in 94.9% (37/39) eyes; lagophthalmos was relieved in 80.7% (67/83) eyes. In patients with UER, the margin reflex distance was lowered from 8.0 (7.5, 8.0) mm to 3.5 (3.4, 4.0) mm (Z=-6.587, P<0.01). The upper scleral show was lowered from 3.0 (3.0, 3.5) mm to 0 mm (Z=-6.616, P<0.01). In patients with LER, the margin reflex distance was lowered from 8.5 (7.5, 9.0) mm to 5.5 (5.5, 6.0) mm (Z=-5.979, P<0.01). The lower scleral show was lowered from 3.0 (2.5, 3.5) mm to 0.0 (0.0, 0.5) mm (Z=-5.965, P<0.01). In total, 71.3% (57 cases) of the patients acquired good outcomes, 22.5% (18 cases) acquired acceptable outcomes, and 6.3% (5 cases) had recurrence, and no significant difference was found between the patients with UER and LER (33, 8, 2 cases vs. 24, 10, 3 cases, Z=-1.176, P>0.05). No other complications, such as infection, rejection, and dislocation, were observed. Conclusion: AXDM as a spacer graft can be a reasonable and safe alternative for eyelid retraction in TAO patients, achieving both the functional and aesthetic improvements. (Chin J Ophthalmol, 2019, 55: 821-827).

Ação da matriz inorgânica de osso bovino (Bonefill®) na neoformação óssea em ratos submetidos ao alcoolismo experimental: análise histológica e morfométrica / Action of inorganic bovine bone Matrix (Bonefill®) on bone formation in rats submitted to experimental alcoholism: histological and morphometric analysis

O desequilíbio no turnover ósseo decorrente dos efeitos do alcoolismo crônico está relacionado à apoptose dos osteócitos, diminuição da espessura do osso medular e cortical e pelas alterações na atividade e diferenciação de osteoblastos. Devido à necessidade de tratamentos regenerativos e reconstrutivos associado ao alcoolismo, os xenoenxertos tem providenciado uma possibilidade terapêutica como material de preenchimento de defeitos ósseos. Em vista disso, este trabalho teve como objetivo analisar o comportamento do biomaterial Bonefill® em defeitos críticos realizados em calvária de ratos, comparar a interferência do alcoolismo experimental na neoformação óssea, além de avaliar a influência do tipo de dieta líquida sobre a massa corporal dos animais. Foram utilizados 40 ratos machos (Rattus norvegicus) da linhagem Wistar, com 60 dias de idade, separados aleatoriamente em Grupo Controle (GC) os animais receberam água como dieta líquida e Grupo Experimental (GE) os animais receberam etanol a 25%, cada grupo composto por 20 ratos. O GC foi sub-dividido em GAC (Grupo Água Coágulo) correspondente ao defeito direito na calota craniana do animal e GAB (Grupo Água Biomaterial), defeito do lado esquerdo do animal. O GE foi sub-dividido em GEC (Grupo Etanol Coágulo) correspondente ao defeito direito da calota craniana e GEB (Grupo Etanol Biomaterial) defeito do lado esquerdo do animal. Foi realizada uma osteotomia circular de 5 mm de diâmetro no osso parietal direito e esquerdo. Os defeitos GAC e GEC foram preenchidos com coágulo sanguíneo e os defeitos GAB e GEB com osso bovino cortical inorgânico. Cinco animais de cada grupo foram eutanasiados nos períodos de 10, 20, 40 e 60 dias pós-cirúrgico. Os resultados da análise histológica mostraram que no período de 10 dias, no GAB e GEB as partículas do enxerto ósseo estavam circundadas por tecido...

The imbalance in bone turnover resulting from the effects of chronic alcoholism is related to apoptosis of osteocytes, decrease of trabecular and cortical bone thickness and changes in activity and differentiation of osteoblasts. Due to the need for regenerative and reconstructive treatments associated with alcoholism, xenografts has provided a therapeutic possibility as a filling material of bone defects. Therefore, the aims of this study were to analyze the Bonefill® biomaterial behavior in critical defects created on the calvaria of rats; to compare the interference of experimental alcoholism in bone formation, as well as to evaluate the influence of 2 type of liquid diet on animal body weight. 40 male Wistar rats were used (Rattus norvegicus), with 60 days of age. The rats were randomly separated into Control Group (CG, nº = 20), which received water as liquid diet and Experimental Group (EG, nº = 20), these rats consumed ethanol 25%. CG was subdivided into WCG (Water Clot Group), corresponding to the right calvaria defect and WBG (Water Biomaterial Group), left side defect of the calvaria. EG was subdivided into ECG (Ethanol Clot Group), corresponding to the right calvaria defect and EBG (Ethanol Biomaterial Group), left side defect of the calvaria. A circle osteotomy of 5 mm in diameter was performed in the right and left parietal bone. The bone defects in WCG and ECG were filled with blood clot and the defects in WBG and EBG were filled with inorganic bovine bone. 5 animals from each group were euthanized at periods of 10, 20, 40 and 60 days after surgery. The histological analysis showed that at 10 days, WBG and EBG, the particles of bone graft were surrounded by granulation tissue and inflammatory cells, it also showed a small immature bone formation mainly at the margins of the defects. At 20 days it was observed blood vessels in WBG and EBG and some graft particles partially surrounded by new bone...

Clinical effect of bioengineered cornea and in vivo confocal microscopy observation after human lamellar keraplasty / 中华实验眼科杂志

Background Xenotransplantation is arousing more attention of researchers because of the lack of corneal donors.Biological corneal scaffolds constructed by porcine corneal acellular stroma appears to have an acceptable biocompatibility.However,its clinical effects and the histomorphological features in the corneal tissue of receipts' are still unclear.Objective This study was to evaluate the viability of bioengineered corneas as a new material of human lamellar keratoplasty and observe the in viva biological features after human keratoplasty under the laser confocal microscope.Methods A prospective serial cases observational study was carried out.Fifteen eyes of 15 patients with infectious keratitis were enrolled in Henan Eye Hospital from February to August 2014 under the approval of Ethic Committee of Henan Eye Hospital and informed consent of each patient, including 4 eyes of fungal keratitis,1 eye of bacterial keratitis, 9 eyes of mixed infectious keratitis and 1 eye of leucoma.Corneal lamellar transplantation was performed on the eyes with the bioengineered corneas as grafts and the follow-up time was one year.The survival of grafts was assessed and scored, and the indices including corneal transparency,neovascularization, graft lysis or inflammatory recurrence and visual acuity (logMAR) were evaluated.The morphology and density of corneal epithelial cells and endothelial cells, corneal stroma and subepithelial neural fibers were examined by laser confocal microscope 3,6,9 and 12 months after surgery.Results Postoperative inflammatory response was seen 3 days and disappeared 7 days after surgery.The grafts were clear 1 month after surgery, and no corneal dissolution was found during the follow-up duration.Glaucoma occurred in 1 eye at 6 months and graft rejection occurred in another eye 12 months after surgery.The logMAR, corneal transparency scores and corneal neovascularization scores improved after surgery in comparison with before surgery,with a significant difference among various time points (x2 =92.63,59.37,10.50 ,all at P＜0.05).Complete epithelization of grafts was seen.Compared with the contralateral eyes,the morphology of epithelial cells was similar and endothelial cells were enlarged in the operated eyes.In addition,no stromal cell structure was seen in the corneal stroma in the operative eyes.Subepithelial nerve fibers appeared in 8 eyes at 6 months, but the fiber density was lower in the operated eyes than that in the contralateral eyes.Significant difference was found in epithelial cell density among different time points (F=1.48, P =0.22).The endothelial cell densities were (2 542 ± 119), (1 895 ± 129), (1 869 ± 135), (1 854 ± 101) and (1 844 ± 103)/mm2 before surgery and 3, 6, 9 and 12 months after surgery, showing significant differences between preoperation and postoperative time points (all at P＜0.05).The subepithelial nerve fibers densities were (1.26± 0.13),(3.62±0.81) and (5.98±0.44) mm/mm2 at 6,9 and 12 months after surgery,with significant differences between adjacent two time points (t'=-8.16 ,-7.24;both at P=0.00).Conclusions Bioengineered corneal grafts survive well in human eye after lamellar transplantation,which can reconstruct ocular surface and improve the visual acuity.Biological cornea can replace human corneal materials.

Feasibility study on the application of the heterogeneous de protein cancellous bone in the treatment of lumber intertransverse process spinal fusion / 中国医师杂志

Objective To investigate application feasibility of the heterogeneous de protein cancellous bone in the treatment of lumber intertransverse process spinal fusion.Methods Thirty 6 ～ 8 month healthy male goats were selected to make intertransverse bone bed,and were randomly divided into groups Ⅰ and Ⅱ,with 15 in each group.Group Ⅰ was the left side implanted the tissue engineering bone (A group),and the right side implanted recombinant human bone morphogenetic protein-2 (rhBMP-2) composite bone (B group);Group Ⅱ was the left implanted autologous bone (C group),and the right side implanted simple heterogeneous de protein cancellous bone (D group).Each group was observed with the Xray,histological morphology,and maximum bending load.Results (1) In groups B and D,postoperative 4-,8-and 12-week X-ray scores were lower than that of group C (P ＜0.05);In group A,postoperative 4-,8-and 12-week X-ray score were (5.30 ± 0.41) points,(8.54 ± 0.89) points,and (11.25 ± 0.91)points,compared to group C,without statistically significant difference (P ＞ 0.05);(2) For groups A,B and D,postoperative 4-and 8-week histological scores were significantly lower than those in group C (P ＜0.05).For group A,postoperative 4-and 8-week histological scores were significantly higher than those of groups B and D (P ＜0.05).The histological scores of groups B and D postoperative 12 weeks were lower than those of group C (P ＜0.05).The histological score of group A postoperative 12 weeks was (11.04 ± 1.52) points,compared to group C without statistically significant difference (P ＞ 0.05);(3) The maximum bending load of groups B and D was lower than that of group C (P ＜ 0.05).The maximum bending load of group A was (60.32 ± 10.10) N,compared to group C without statistically significant difference (P ＞ 0.05).Conclusions The construction of tissue engineered bone by the heterogeneous de protein cancellous bone,its osteogenesis is close to autogenous bone,but simple heterogeneous de protein cancellous bone osteogenesis is poor.

Is autologous or heterologous pericardium better for valvuloplasty? A comparative study of calcification propensity.

Pericardial calcification is detrimental to the long-term durability of valvuloplasty. However, whether calcification susceptibility differs between heterologous and autologous pericardium is unclear. In this study, we compared the progression of calcification in vivo between autologous and heterologous pericardium. We randomly divided 28 rabbits into 4 equal groups. Resected rabbit pericardium served as autologous pericardium, and commercial bovine pericardium served as heterologous pericardium. We subcutaneously embedded one of each pericardial patch in the abdominal walls of 21 of the rabbits. The 7 control rabbits (group A) received no implants. The embedded samples were removed at 2 months in group B, at 4 months in group C, and at 6 months in group D. Each collected sample was divided into 2 parts, one for calcium-content measurement by means of atomic-absorption spectroscopy, and one for morphologic and histopathologic examinations. When compared with the autologous pericardium, calcium levels in the heterologous pericardium were higher in groups B, C, and D (P <0.0001, P <0.0002, and P <0.0006, respectively). As embedding time increased, calcium levels in the heterologous pericardium increased faster than those in the autologous, especially in group D. Disorganized arrangements of collagenous fibers, marked calculus, and ossification were seen in the heterologous pericardium. Inflammatory cells-mainly lymphocytes and small numbers of macrophages-infiltrated the heterologous pericardium. The autologous pericardium showed a stronger ability to resist calcification. Our results indicate that autologous pericardium might be a relatively better choice for valvuloplasty.

Research progress of patient-derived xenograft model / 国际外科学杂志

Tumor cell line culture technologies emerged as a strong impetus to the development of tumor biology research.However,cell line tumor model presented limited predictive value and instable properties in the clinical translational research of new cancer therapies.Recently Patient-derived Xenograft Model (PDX) has aroused researcher's attention and been widely applied to new cancer therapy research.This new model could highly retain the stroma heterogeneity、histological characteristics and molecular diversity of the original tumor,and is expected to bring new breakthroughs in individualized treatment of tumor patients.

Thin-thicknessversus blade-thickness micro-skin pulping covered with heterogeneous skin for repair of burn wounds / 中国组织工程研究

BACKGROUND:Autologous micro-skin graft covered with alogeneic skin has become a major means for repair of extremely severe burn wounds. Due to the limitation of the source of alogeneic skin, heterogeneous skin (pigskin) or artificial skin serves as a vector to cover the wound on the clinical use. OBJECTIVE: To observe the curative effect of thin-thickness micro-skin pulping covered with heterogeneous skin for repair of burn wounds in comparison with blade-thickness micro-skin pulping covered with heterogeneous skin. METHODS:A self-control study was performed in 36 patients with severe burns of bilateral limbs. There were 42 pairs of wounds, 32 of which were at joint sites. One or two pairs of III-degree burns treated with escharectomy were selected from each patient for self-control comparison. Covered with heterogeneous skin, thin-thickness micro-skin pulping and blade-thickness micro-skin pulping were used in the trial and control groups, respectively. The expansion ratio was controled at 1:8-1:12 in al patients. Wound healing time, degree of scar hyperplasia within 6 months to 2 years after transplantation, and ratio of reconstruction surgery at joint sites were observed and compared. The removed scars by surgery were analyzed based on the total score of the Vancouver Scar Scale. RESULTS AND CONCLUSION: The average wound healing time was (44.7±1.24) days in the trial group and (49.6±1.41) days in the control group, and there was a significant difference between the two groups (P 0.05). The reconstructive surgery ratio of the trial group was 38%, significantly lower than that of the control group (59.38%;P < 0.01). The total score on the Vancouver Scar Scale was less in the trial group than the control group (P < 0.05). These findings suggest that the thin-thickness micro-skin covered with heterogeneous skin is likely to be a better treatment to repair large ful-thickness skin burn by increasing the thickness of micro-skin, and it can obtain better wound healing quality.

Alpha-Gal antigen and immunity risk control of animal-derived medical devices / 中国组织工程研究

BACKGROUND:Medical devices from animals are commonly used in clinical application. Despite their efficiency is widely accepted, their safety, especialy immunity has been concerned. OBJECTIVE:To investigate immunity risk control to medical devices from animals for safety consideration. METHODS:Using “α-Gal antigen, immunity, xenotransplantation” in Chinese and English as the key words, the first author conducted a computer search of Science direct database (www.sciencedirect.com), Wiley-Blackewel database (http://onlinelibrary.wiley.com) and Wanfang database (www.wanfang.com.cn) through screening the titles and abstracts. RESULTS AND CONCLUSION:Increasing evidence shows that, Gal α1-3Gal antigen (α-Gal antigen) is recognized as the major antigen and abundantly expressed on glycoconjugates of non-primate mammals and New World monkeys. In contrast, the α-gal epitope is not expressed on glycoconjugates of humans and Old World monkeys. Instead, they produce a very large amount of natural anti-α-Gal antibody that specificaly binds the α-gal epitope. The binding of human natural anti-α-Gal to α-gal epitopes expressed on non-primate mammal animals was expected to be unique immunological barrier in xenotransplantation. Therefore, it is important to choose raw materials, reduce or eliminate the α-Ggal epitope, establish highα-Ggal epitope detection methods with high sensitivity and good repeatability for achieving a greater safety and efficiency of medical devices from animals.

Xenotransplante de células mesenquimais de tecido adiposo humano em modelo de lesão de raízes ventrais da medula espinal de rato / Xenotransplantation of mesenchymal stem cells from human adipose tissue in a rat model of ventral root lesions of the spinal cord

A avulsão de raízes motoras, na interface do sistema nervoso central e periférico, já bem descrito na literatura, promove uma significativa perda sináptica com degeneração de cerca de 80% dos motoneurônios afetados. Não existem estratégias eficazes que propiciem uma reversão ou amenização deste quadro, mas alguns estudos já mostram que o passo fundamental é preservar os motoneurônios afetados. Pesquisas em diferentes áreas com células-tronco (CT) adultas estão sendo realizadas nos últimos anos e apresentam resultados promissores para a medicina regenerativa. Investigações recentes têm apontado para diferentes fontes de CT em tecidos adultos tais como de medula óssea, de sangue de cordão umbilical, tecido muscular, tecido nervoso, líquido amniótico entre outras. De modo geral, estas células apresentam como características principais a capacidade de proliferação e a diferenciação para outros tipos celulares. Entretanto, os principais problemas para o uso clínico das CT adultas são: i) pequena quantidade de células multipotentes, ii) o controle da diferenciação, iii) insuficiência no número de células viáveis e iiii) difícil obtenção. Como alternativa às dificuldades anteriormente citadas, o tecido adiposo tem sido foco de intensos estudos, pois este tecido possui rica fonte de células pluripotentes, além de apresentarem características positivas como fácil acesso ao tecido adiposo subcutâneo, obtenção em quantidade abundante e processo de isolamento celular relativamente simples. Apesar deste tecido apresentar organização complexa, é na fração celular do estroma vascular que se encontra uma rica população de células pluripotentes. Dados de literatura demonstram que as células mesenquimais derivadas de tecido adiposo (AT-MSC - Células mesenquimais de tecido adiposo), mediante incubação com meios de cultura variados, diferenciam-se em adipócitos, osteócitos, mioblastos, hepatócitos, células vasculares entre outras.

It is well described in the literature that avulsion motor at the interface of the central and peripheral nervous system, promotes a significant loss of synaptic degeneration and 80% of motor neurons death. There is no effective strategies that favor a reversal or mitigation of this framework, but some studies have shown that the key step is to preserve motor neurons affected. Researches in different areas with stem cell (CT) adults are being undertaken in recent years and show promising results for regenerative medicine. Recent investigations have pointed to different sources of CT in adult tissues such as bone marrow, umbilical cord blood, brain, muscle tissue, amniotic fluid, among others. Generally, these cells have as main characteristics capacity for proliferation and differentiation to other cell types. However, the main problems for the clinical use of adult SC are: i) small amount of multipotent cells, ii) differentiation control, iii) low number of viable cells and iiii) difficulty to obtain. As an alternative to the difficulties mentioned above, adipose tissue has been the focus of intense study, because this tissue has a rich source of stem cells, in addition to having positive characteristics such as easy access to subcutaneous adipose tissue, obtained in abundant quantities and isolation process relatively simple. Despite the complex tissue organization, the stromal vascular fraction is rich of pluripotent population cells. Literature data show that stromal cells derived from adipose tissue (AT-MSC-adipose tissue mesenchymal stem cells) can differentiate by incubation with various culture media into adipocytes, osteocytes, myoblasts, hepatocytes, vascular cells, among others. The AT-MSC differentiation into neuronal cells is still subject of discussion and criticism in literature, since no established protocol has induced differentiation into function neuronal cells.

Resposta tecidual ao implante ósseo xenógeno inorgânico variando-se o método de esterilização: avaliação histomorfológica e histomorfométrica / Tissue response to inorganic xenograft implant: histomorphological and histomorphometrical evaluation

Proposição: Este estudo avaliou a resposta tecidual ao implante xenógeno inorgânico de osso bovino, por meio de análise histomorfológica e histomorfométrica, variando-se o método de esterilização. Materiais e Método: Discos de 8 mm costela bovina foram obtidos por processamento específico para remoção de parte orgânica e foram esterilizados por meio de autoclavagem ou radiação gama. Em seguida, 20 coelhos brancos (Nova Zelândia) foram cirurgiados para instalação dos discos na face lateral dos gônios mandibulares, bilateralmente, através de parafuso de fixação de enxertos, originando dois grandes grupos: Grupo EA - implante autoclavado; Grupo EI – implante gama-irradiado. As lâminas foram obtidas nos períodos de 15 e 45 dias pós-operatórios e as imagens teciduais foram analisadas qualitativa e quantitativamente. Resultados: O teste de Kruskal-Wallis foi aplicado e não identificou diferença significativa entre as medidas lineares das interfaces osso/implante (BIC) dos grupos dentro dos mesmos períodos (15 dias: p=0,100; 45 dias: p=0,940). Conclusão: De acordo com a metodologia aplicada, foi possível concluir que o estabelecimento da integração osso/implante cursou com atraso quando o implante foi esterilizado por radiação, porém, com a evolução da reparação, o método de esterilização não ocasionou alterações significativas no período final

Proposition: This study evaluated the tissue response to the implant inorganic xenogenic bovine bone through the histomorphological analysis, varying the method of sterilization. Materials and Methods: Discs of 8 mm bovine rib were obtained by specific processing to remove organics phase and were sterilized by autoclaving or gamma radiation. Then, 20 white rabbits (New Zealand) were operated for discs installation on gonion external side of mandibular, bilaterally, through screw grafts, yielding two large groups: EA - implant autoclaved; EI Group - gamma-irradiated implant. Slides were obtained at 15 and 45 days post-operative tissue and the images were analyzed qualitatively and quantitatively. Results: The Kruskal-Wallis test was used and no difference was found between linear interfaces of the bone / implant (BIC) groups within the same period (15 days: p = 0.100; 45 days: p = 0.940). Conclusion: According to the methodology, it was concluded that the establishment of integration bone / implant occurred later when the implant was sterilized by radiation in initial period, but with the evolution of repair, the method of sterilization did not cause significative changes in the final period

Análise tomográfica da formação óssea em defeito segmentar na mandíbula de coelho preenchido com bloco de osso bovino liofilizado / Tomographic analysis of bone formation in segmental defects created in the mandible of rabbits filled with lyophilized bovine bone block

O recente aumento da procura por implantes osseointegráveis consequentemente levou ao aumento dos procedimentos de enxertos ósseos. Com isso, novos materiais têm surgido para estes procedimentos. Um destes materiais é o osso bovino integral (OBIN), cujo diferencial é o seu método de processamento, que visa manter suas características o mais próximas possível ao osso in natura. Por se tratar de um material novo, ainda existem poucos estudos avaliando seu desempenho, sendo a maioria deles estudos pré-clínicos testando sua biocompatibilidade. Portanto, o objetivo deste trabalho foi avaliar o desempenho do OBIN na região maxilofacial através de um modelo experimental em animais. Foram criados defeitos ósseos na base da mandíbula de coelhos, onde foram enxertados blocos de OBIN nos grupos experimentais e deixados vazios nos grupos controle. Os animais foram sacrificados nos tempos 0 (imediatamente após a cirurgia), 3 e 6 meses após o procedimento cirúrgico. As mandíbulas foram analisadas através de tomografias computadorizadas de feixe cônico, onde foi analisada a regeneração óssea qualitativamente e quantitativamente. Na análise qualitativa observou-se que aos três e seis meses, nos animais do grupo controle, não houve regeneração total, restando um defeito côncavo na base da mandíbula, confirmando que o defeito criado possuía tamanho crítico. No grupo experimental, no tempo 0, observou-se grande variação de densidade entre os enxertos e esta variação pareceu influenciar seu desempenho, havendo mais regeneração óssea nos menos densos. No tempo 3, todos os enxertos haviam integrados, com perda de densidade, sugerindo uma reabsorção parcial. Aos seis meses, a reabsorção e regeneração pareciam mais avançadas do que aos três meses. Na análise quantitativa houve diferença estatisticamente significante nos grupos controles entre os tempos 0 e os tempos 3 e 6. Nos grupos experimentais não houve diferença entre os tempos e na comparação entre os grupos controles...

The recent increase in the demand for dental implants consequently led to increased bone grafting procedures. Therefore, new materials have emerged for these procedures. One of these materials is integral bovine bone (IBB) whose differential is its processing, which aims to maintain its characteristics as close as possible to the raw bone. Because it is a new material, there are only a few studies evaluating its performance, with the majority of them constituted of preclinical studies testing its biocompatibility. For this reason, the aim of this study was to evaluate the performance of the IBB at the maxillofacial region through an experimental model in animals. Bone defects were created on the basis of the mandible of rabbits, which were grafted with blocks of IBB in the experimental groups, while control groups were left empty. The animals were sacrificed at time 0 (immediately after surgery), 3 and 6 months after surgery. The jaws were analyzed using cone beam computed tomography, where bone regeneration was analyzed qualitatively and quantitatively. Qualitative analysis showed that at three and six months, in the control group, there was not full regeneration, leaving a concave defect in the base of the mandible, confirming that the defect created had critical size. In the experimental group, at time 0, there was wide variation in density between the grafts and this variation appeared to influence their performance, seeming to be more bone regeneration in less dense ones. At time 3, all grafts were integrated, and a density loss, suggesting a partial resorption of the graft, was also observed. At six months, resorption and regeneration seemed more advanced than at three months. The quantitative analysis did not showed statistically significant difference in controls between time 0 and times 3 e 6. In experimental groups there was no difference between times and comparison between control and experimental groups were statistically...

Articular cartilage defect treated with biological osteochondral xenogenic graft transplantation / 中国组织工程研究

BACKGROUND:The methods used to repair articular cartilage defects currently have the cons and pros. Fibrocartilages are commonly used to repair tissues, and the fibrocartilage lacks of the tissue biomechanical properties and chemical properties of normal hyaline cartilage. OBJECTIVE:To investigate the feasibility of biological osteochondral xenogenic graft transplantation to repair articular cartilage defects. METHODS:The normal goats were randomly divided into two groups. The donor pig knee joints were the experimental group. Cylindrical osteochondral with the diameter of 4.5 mm and length of 10 mm were col ected with the Smith&Nephew osteochondral transplantation device, and the patented technology was used for deantigen. The donor goat knee joint osteochondrals were the control group and preserved with cryopreservation. The lesions on femoral trochlea and weight-bearing surface of medial condyle were selected respectively for osteochondral implantation, and the animals were sacrificed at 16 and 32 weeks after operation for the general and pathological section observation. RESULTS AND CONCLUSION:General observation in the experimental showed that the lesions were covered by fibroid tissue;some cartilage of the grafts turned yel ow and there was clear boundary between the surface and the peripheral cartilages;the general and section observation under microscope showed that lesions of the control group were covered by the grafts basical y, and cracks could be seen on the edge of the transplant part. The results show that there is difference between effects of biological osteochondral xenogenic graft transplantation and osteochondral al ograft transplantation for the repairing of articular cartilage defects, and osteochondral al ograft transplantation bas better effect.

Resposta tecidual ao implante ósseo xenógeno inorgânico variando-se o método de esterilização: avaliação histomorfológica e histomorfométrica / Tissue response to inorganic xenograft implant: histomorphological and histomorphometrical evaluation

Proposição: Este estudo avaliou a resposta tecidual ao implante xenógeno inorgânico de osso bovino, por meio de análise histomorfológica e histomorfométrica, variando-se o método de esterilização. Materiais e Método: Discos de 8 mm costela bovina foram obtidos por processamento específico para remoção de parte orgânica e foram esterilizados por meio de autoclavagem ou radiação gama. Em seguida, 20 coelhos brancos (Nova Zelândia) foram cirurgiados para instalação dos discos na face lateral dos gônios mandibulares, bilateralmente, através de parafuso de fixação de enxertos, originando dois grandes grupos: Grupo EA - implante autoclavado; Grupo EI – implante gama-irradiado. As lâminas foram obtidas nos períodos de 15 e 45 dias pós-operatórios e as imagens teciduais foram analisadas qualitativa e quantitativamente. Resultados: O teste de Kruskal-Wallis foi aplicado e não identificou diferença significativa entre as medidas lineares das interfaces osso/implante (BIC) dos grupos dentro dos mesmos períodos (15 dias: p=0,100; 45 dias: p=0,940). Conclusão: De acordo com a metodologia aplicada, foi possível concluir que o estabelecimento da integração osso/implante cursou com atraso quando o implante foi esterilizado por radiação, porém, com a evolução da reparação, o método de esterilização não ocasionou alterações significativas no período final

Proposition: This study evaluated the tissue response to the implant inorganic xenogenic bovine bone through the histomorphological analysis, varying the method of sterilization. Materials and Methods: Discs of 8 mm bovine rib were obtained by specific processing to remove organics phase and were sterilized by autoclaving or gamma radiation. Then, 20 white rabbits (New Zealand) were operated for discs installation on gonion external side of mandibular, bilaterally, through screw grafts, yielding two large groups: EA - implant autoclaved; EI Group - gamma-irradiated implant. Slides were obtained at 15 and 45 days post-operative tissue and the images were analyzed qualitatively and quantitatively. Results: The Kruskal-Wallis test was used and no difference was found between linear interfaces of the bone / implant (BIC) groups within the same period (15 days: p = 0.100; 45 days: p = 0.940). Conclusion: According to the methodology, it was concluded that the establishment of integration bone / implant occurred later when the implant was sterilized by radiation in initial period, but with the evolution of repair, the method of sterilization did not cause significative changes in the final period