Small Intestinal Submucosa Hydrogel Loaded With Gastrodin for the Repair of Achilles Tendinopathy.

Achilles tendinopathy (AT) is an injury caused by overuse of the Achilles tendon or sudden force on the Achilles tendon, with a considerable inflammatory infiltrate. As Achilles tendinopathy progresses, inflammation and inflammatory factors affect the remodeling of the extracellular matrix (ECM) of the tendon. Gastrodin(Gas), the main active ingredient of Astrodia has anti-inflammatory, antioxidant, and anti-apoptotic properties. The small intestinal submucosa (SIS) is a naturally decellularized extracellular matrix(dECM)material and has a high content of growth factors as well as good biocompatibility. However, the reparative effects of SIS and Gas on Achilles tendinopathy and their underlying mechanisms remain unknown. Here, it is found that SIS hydrogel loaded with gastrodin restored the mechanical strength of the Achilles tendon, facilitated ECM remodeling, and restored ordered collagen arrangement by promoting the translocation of protein synthesis. It also decreases the expression of inflammatory factors and reduces the infiltration of inflammatory cells by inhibiting the NF-κB signaling pathway. It is believed that through further research, Gas + SIS may be used in the future for the treatment of Achilles tendinopathy and other Achilles tendon injury disorders.

Therapeutic application of decellularized porcine small intestinal submucosa scaffold in conjunctiva reconstruction.

The objective of this study was to investigate the biological feasibility and surgical applicability of decellularized porcine small intestinal submucosa (DSIS) in conjunctiva reconstruction. A total of 52 Balb/c mice were included in the study. We obtained the DSIS by decellularization, evaluated the physical and biological properties of DSIS in vitro, and further evaluated the effect of surgical transplantation of DSIS scaffold in vivo. The histopathology and ultrastructural analysis results showed that the scaffold retained the integrity of the fibrous morphology while removing cells. Biomechanical analysis showed that the elongation at break of the DSIS (239.00 ± 12.51%) were better than that of natural mouse conjunctiva (170.70 ± 9.41%, P < 0.05). Moreover, in vivo experiments confirmed the excellent biocompatibility of the decellularized scaffolds. In the DSIS group, partial epithelialization occurred at day-3 after operation, and the conjunctival injury healed at day-7, which was significantly faster than that in human amniotic membrane (AM) and sham surgery (SHAM) group (P < 0.05). The number and distribution of goblet cells of transplanted DSIS were significantly better than those of the AM and SHAM groups. Consequently, the DSIS scaffold shows excellent biological characteristics and surgical applicability in the mouse conjunctival defect model, and DSIS is expected to be an alternative scaffold for conjunctival reconstruction.

Small intestinal submucosa graft bulbar urethroplasty is a viable technique: results compared to buccal mucosa graft urethroplasty after propensity score matching.

PURPOSE: Small intestinal submucosa (SIS) graft urethroplasty has been employed to decrease buccal mucosa morbidity and facilitate the procedure. The first published series had a short follow-up, inhomogeneous patient selection, and a lack of a control group. Our purpose is to report treatment outcomes at 13 years in a propensity score-matched cohort comparing bulbar urethroplasty with SIS (SISU) or buccal mucosa (BMU). METHODS: From our institutional database of 1132 bulbar urethroplasties, we used propensity score matching with the nearest-neighbor method without replacement to generate a study sample of 25 BMU and 25 SISU. Failure was defined as any treatment after urethroplasty. Survival analyses were used to analyze treatment failure occurrence with data censored at 156mo. RESULTS: Matching resulted in a complete correction of bias between the two samples except for the follow-up duration, which was slightly longer in the SIS group. The cumulative treatment success probability of BMU and SISU at 156mo was 83.4% and 68%, respectively. At multivariable Cox regression, SIS graft, previous urethrotomy, stricture length, and lower postoperative Qmax (within 2mo after catheter removal) were predictors of failure. Stricture length had a more remarkable effect in SISU, with estimated survival probabilities from the Cox model lower than 80% in strictures > = 3 cm. CONCLUSION: SIS has poorer outcomes compared to BM but may still be useful when BM grafting is not possible. The best candidates for SISU, with similar success to BMU, are patients with strictures shorter than 3 cm, preferably without a history of DVIU.

Reinforcing decellularized small intestine submucosa with cellulose acetate nanofibrous and silver nanoparticles as a scaffold for wound healing applications.

BACKGROUND: The formation of chronic wounds accounts for considerable costs in health care systems. Despite the several benefits of decellularized small intestinal submucosa (SIS) as an appropriate scaffold for different tissue regeneration, it has shortcomings such as lack of antibacterial features and inappropriate mechanical properties for skin tissue regeneration. We aimed to examine the efficacy and safety of decellularized SIS scaffold enhanced with cellulose acetate (CA) and silver (Ag) nanoparticles (NPs) for healing full-thickness wounds. METHODS AND RESULTS: The scaffolds were prepared by decellularizing bovine SIS and electrospinning CA/Ag nanoparticles and characterized using a transmission electron microscope (TEM), scanning electron microscope (SEM), tensile testing, and X-ray diffraction. In vivo evaluations were performed using full-thickness excisions covered with sterile gauze as the control group, SIS, SIS/CA, and SIS/CA/Ag scaffolds on the dorsum of twenty male Wistar rats divided into four groups randomly with 21-days follow-up. All in vivo specimens underwent Masson's trichrome (MT) staining for evaluation of collagen deposition, transforming growth factor-ß (TGF-ß) immunohistochemistry (IHC), and Haematoxylin Eosin (H&E) staining. The IHC and MT data were analyzed with the ImageJ tool by measuring the stained area. The TEM results revealed that Ag nanoparticles are successfully incorporated into CA nanofibers. Assessment of scaffolds hydrophilicity demonstrated that the contact angle of SIS/CA/Ag scaffold was the lowest. The in vivo results indicated that the SIS/CA/Ag scaffold had the most significant wound closure. H&E staining of the in vivo specimens showed the formation of epidermal layers in the SIS/CA/Ag group on day 21. The percentage of the stained area of MT and TGF-ß IHC staining's was highest in the SIS/CA/Ag group. CONCLUSION: The decellularized SIS/CA/Ag scaffolds provided the most significant wound closure compared to other groups and caused the formation of epidermal layers and skin appendages. Additionally, the collagen deposition and expression of TGF-ß increased significantly in SIS/CA/Ag group.

Application of multi-layer porcine small intestinal submucosa for the reconstruction of deep corneal defects in cats.

OBJECTIVE: This study documented the application of porcine small intestinal submucosa (SIS) as a stand-alone scaffold for treating deep corneal defects in cats. METHODS: Medical records of 20 cats with deep stromal ulcers, perforations, or corneal sequestra that underwent surgical treatment with SIS grafts between 2021 and 2022 were retrospectively reviewed. Data on re-epithelialization time, corneal transparency score, and complications were collected to analyze the reconstruction of deep corneal defects after SIS biomaterial implantation. RESULTS: All cats were unilaterally affected. The corneal defects varied in size, with a median diameter of 8.3 mm (range: 3-15 mm). Re-epithelialization of the SIS graft was completed 16-32 days after surgery (median, 22.3 days). No, mild, or moderate corneal transparency was detected in 90% of the cases. Complications were observed in eight cases (40%), including aqueous leakage (10%), partial SIS malacia (25%), and persistent bullous keratopathy (5%). The follow-up period ranged 90-725 days, with a median duration of 255 days. The SIS graft was successfully applied as a single scaffold in 17 of 20 cases (85%). CONCLUSION: The results of this study suggest that the application of commercial SIS is an effective surgical technique for managing deep corneal defects in cats.

Reconstruction of deep and perforating corneal defects in dogs-A review (Part II/III): Biomaterials and keratoprosthesis.

The surgical reconstruction of severe corneal ulcers is a common and crucial component of the clinical practice of veterinary ophthalmology. Numerous surgical techniques are used in dogs for corneal reconstruction, and these techniques may be categorized by the material used to repair the corneal lesion. The first part of the present review described procedures that utilize autogenous ocular tissues, homologous donor tissues, and heterologous donor tissues. In this second part of the review, the categories of biomaterials and keratoprosthetics will be summarized. Biomaterials that are reported for use in dogs include amniotic membrane, porcine urinary bladder acellular matrix, porcine small intestinal submucosa, acellular porcine corneal stroma, and other miscellaneous soft tissue and cartilage grafts (e.g., preserved equine renal capsule, autologous omentum, autologous buccal mucosa membrane, bovine pericardium, and homologous peritoneum). Descriptions of keratoprosthesis surgery in dogs are currently limited, but the use of artificial corneal transplants hold promise for dogs with severe, vision-compromising corneal disease that is not amenable to other reconstruction techniques. This review describes the results of experimental studies evaluating these graft materials in dogs, and it will summarize the findings and outcomes of the clinical articles published in each material category. Reporting inconsistencies and areas where additional research is required will be highlighted to help guide future studies in this area. A major aim of this review is to help identify potential subjects that could be evaluated in future investigations and that might lead to refinements in clinical practice.

[Effects of different polymers on biomimetic mineralization of small intestine submucosal scaffolds].

OBJECTIVE: To explore the effects of different polymers on in vitro biomimetic mineralization of small intestinal submucosa (SIS) scaffolds, and to evaluate the physicochemical properties and biocompatibility of the SIS scaffolds. METHODS: The SIS scaffolds prepared by freeze-drying method were immersed in simulated body fluid (SBF), mineralized liquid containing polyacrylic acid (PAA) and mine-ralized liquid containing PAA and polyaspartic acid (PASP). After two weeks in the mineralized solution, the liquid was changed every other day. SBF@SIS, PAA@SIS, PAA/PASP@SIS scaffolds were obtained. The SIS scaffolds were used as control group to evaluate their physicochemical properties and biocompatibility. We observed the bulk morphology of the scaffolds in each group, analyzed the microscopic morphology by environment scanning electron microscopy and determined the porosity and pore size. We also analyzed the surface elements by energy dispersive X-ray spectroscopy (EDX), analyzed the structure of functional groups by Flourier transformed infrared spectroscopy (FTIR), detected the water absorption rate by using specific gravity method, and evaluated the compression strength by universal mechanical testing machine. The pro-cell proliferation effect of each group of scaffolds were evaluated by CCK-8 cell proliferation method. RESULTS: Under scanning electron microscopy, the scaffolds of each group showed a three-dimensional porous structure with suitable pore size and porosity, and crystal was observed in all the mineralized scaffolds of each group, in which the crystal deposition of PAA/PASP@SIS scaffolds was more regular. At the same time, the collagen fibers could be seen to thicken. EDX analysis showed that the characteristic peaks of Ca and P were found in the three groups of mineralized scaffolds, and the highest peaks were found in the PAA/PASP@SIS scaffolds. FTIR analysis proved that all the three groups of mineralized scaffolds were able to combine hydroxyapatite with SIS. All the scaffolds had good hydrophilicity. The compressive strength of the mineralized scaffold in the three groups was higher than that in the control group, and the best compressive strength was found in PAA/PASP@SIS scaffold. The scaffolds of all the groups could effectively adsorb proteins, and PAA/PASP@SIS group had the best adsorption capacity. In the CCK-8 cell proliferation experiment, the PAA/PASP@SIS scaffold showed the best ability to promote cell proliferation with the largest number of living cells observed. CONCLUSION: Compared with other mineralized scaffolds, PAA/PASP@SIS scaffolds prepared by mineralized solution containing both PAA and PASP have better physicochemical properties and biocompatibility and have potential applications in bone tissue engineering.

Optimization of decellularization methods using human small intestinal submucosa for scaffold generation in regenerative medicine.

Porcine small intestinal submucosa, despite its successful use as a scaffold in regenerative medicine, has innate biomechanical heterogeneity. In this study, we hypothesized that human small intestinal submucosa could be a viable alternative bio-scaffold. For the first time, we characterize submucosal extraction from human small intestine and examine appropriate decellularization methods. In total, 16 human small intestinal submucosal samples were obtained and decellularized using three reported methods of porcine decellularization: Abraham, Badylak, and Luo. For each method, four specimens were decellularized. The remaining four specimens were designated as non-decellularized. We measured the amount of residual DNA and growth factors in decellularized human intestinal samples. Additionally, decellularized human small intestinal submucosa was co-cultured with mouse bone marrow-derived mesenchymal stem cells to examine mesenchymal stem cell survival and proliferation. The reference value for the amount of residual DNA deemed appropriate in decellularized tissue was established as 50 ng/mg of extracellular matrix dry weight or less. Abraham's method most successfully met this criterion. Measurement of residual growth factors revealed low levels observed in samples decellularized using the Abraham and Badylak methods. Co-culture of each small intestinal submucosal sample with mouse bone marrow-derived mesenchymal stem cells confirmed viable cell survival and proliferation in samples derived using protocols by Abraham and Badylak. Abraham's method most successfully met the criteria for efficient tissue decellularization and cell viability and proliferation. Thus, we consider this method most suitable for decellularization of human small intestinal submucosa.

The long-term outcomes of vaginoplasty using acellular porcine small intestinal submucosa grafts in patients with Mayer-Rokitansky-Küster-Hauser syndrome: A case series.

OBJECTIVE: To investigate the long-term outcomes for Mayer-Rokitansky-Küster-Hauser syndrome (MRKH) patients undergoing vaginoplasty using acellular porcine small intestinal submucosa grafts (SIS). DESIGN: A case series. POPULATION: Seventy-eight MRKH syndrome patients and a post-SIS patient who delivered a baby following the world's first robot-assisted uterus transplantation. METHODS: Mayer-Rokitansky-Küster-Hauser syndrome patients were grouped based on the postoperative time and the diagnosis-surgery interval. Outcomes of sexual function and psychological status were assessed using the female sexual function index (FSFI), self-rating scale of body image (SSBI) and self-acceptance questionnaire (SAQ). Anatomical outcomes were measured by clinicians. MAIN OUTCOME MEASURES: The primary outcome was restoration of sexual function, defined by an FSFI score in the 'good' range. Anatomical and psychological outcomes were also analysed. RESULTS: Sexual function was restored in 42.3% (33/78) of patients and the total FSFI score was 23.44 ± 4.43. Three factors (body defect, recognition of physical appearance and willingness to change physical appearance scores) in the SSBI and two in the SAQ decreased as the postoperative time increased. Based on the interval between diagnosis and surgery, the total SSBI score was lower in the short-interval group than in the long-interval group (7.25 ± 5.55 versus 12.04 ± 10.21, p = 0.038). CONCLUSIONS: Nearly half of MRKH patients in our study had good long-term sexual function after SIS vaginoplasty. Sexual function and psychological status improved as postoperative time increased. In addition, reducing the diagnosis to surgery interval was associated with improved psychological function.

Outcome of a novel porcine-derived UBM/SIS composite biological mesh in a rabbit vaginal defect model.

INTRODUCTION AND HYPOTHESIS: To investigate the tissue reactions of a novel porcine-derived urinary bladder matrix/small intestinal submucosa (UBM/SIS) biological mesh and SIS mesh implanted in a rabbit vaginal defect model. METHODS: Thirty-two rabbits were implanted with UBM/SIS mesh (Group A) and SIS mesh (Group B), respectively. Rabbits were sacrificed at 7, 14, 60, and 180 days after implantation. The tensile strength, elongation at break, and elastic modulus of the tissue were measured using biomechanical methods. The inflammatory response, cell infiltration, vascularization, and collagen fibers were observed. RESULTS: Compared with Group B, the tensile strength and elongation at break of group A was higher at 14, 60, and 180 days. The elastic modulus of group A was lower at 180 days. Inflammatory response of group A was milder at 14, 60, and 180 days. There was more cell infiltration in group A at 7 and 14 days. Vascularization was higher in group A at 7 days and 14 days. The order of collagen in group A was better at 14, 60, and 180 days. The proportion of thick red fibers in both groups showed an increasing trend. At 14 days, group A had more thick red fibers. CONCLUSIONS: The novel UBM/SIS composite mesh had a milder inflammatory response; earlier induction of cell infiltration, angiogenesis, and collagen regeneration. Collagen fibers had a better order. It has a higher tensile strength and greater elongation at break, and can be used as a potential material for the treatment of pelvic organ prolapse.

Comparison of Sheares vaginoplasty, vaginoplasty using acellular porcine small intestinal submucosa graft and laparoscopic peritoneal vaginoplasty in patients with Mayer-Rokitansky-Küster-Hauser syndrome.

INTRODUCTION AND HYPOTHESIS: The aim of this study is to compare the perioperative, anatomical and functional outcomes of patients with Mayer-Rokitansky-Küster-Hauser syndrome (MRKHS), undergoing Sheares vaginoplasty, vaginoplasty using acellular porcine small intestinal submucosa (SIS) graft or laparoscopic peritoneal (Davydov) vaginoplasty. METHODS: In this retrospective study, a total of 117 patients with MRKHS undergoing creation of a neovagina from 2017 to 2020 were retrospectively investigated. Comparisons between continuous variables were performed using Student's t-test and between qualitative variables using chi-squared tests. RESULTS: The operative time, return of bowel activity and return to work were the longest in the laparoscopic Davydov group (P < 0.001). The total cost was the highest in the SIS graft group (P < 0.001). The length of the neovagina was 7.9 ± 1.2 cm in the Sheares group, 7.1 ± 0.8 cm in the SIS graft group and 8.1 ± 1.1 cm in the laparoscopic Davydov group. The difference in the length of the neovagina was significant (P < 0.001). There was significant difference in the duration of continuous mould wearing (P < 0.001). There were no significant differences in the total female sexual function index (FSFI) scores or in the satisfaction scores of the male partner among the three groups. CONCLUSION: Sheares vaginoplasty and the vaginoplasty using SIS graft caused less trauma and provided similar functional results to laparoscopic peritoneal vaginoplasty. However, the patients in the Sheares group and SIS graft group needed to wear the mould for a longer duration post-surgery. Sheares vaginoplasty can provide a valuable and economic alternative method for the creation of a neovagina in patients with MRKHS.

Otologic use of porcine small intestinal submucosal graft (biodesign): A MAUDE database review.

OBJECTIVE: To review and summarize reported adverse events related to the use of porcine small intestine submucosal grafts (Biodesign™) in otologic procedures. STUDY DESIGN: Retrospective cross-sectional analysis. SETTING: Food and Drug Administration's Manufacturer and User Facility Device Experience (MAUDE) database. MATERIAL AND METHODS: The MAUDE database was queried for all medical device reports (MDR) related to otologic use of Biodesign™ (Cook Medical, Bloomington, IN) from January 2016 to November 2022. Adverse events (AEs) were identified by reviewing all reports with the basic search term "Biodesign" and "Biodesign, Otologic". Reports were individually reviewed and categorized with special attention to AEs. RESULTS: A total of 500 reports were reviewed. Since FDA approval of Biodesign™ in 2016, there have been 5 adverse events reported for use of Biodesign™ during otologic surgery (tympanoplasty, n = 3; stapes surgery, n = 2). All reported events described patient injury, and all cases required at least one revision surgery. Four cases described significant foreign body inflammatory reactions. Complications included hearing loss (n = 3), severe otalgia (n = 2), persistent perforation (n = 2), vertigo (n = 2), and facial paralysis (n = 1). CONCLUSION: The use of porcine small intestinal submucosal graft has been thought to be a safe and effective option for otologic surgery, with the advantage of availability without graft harvest in minimally invasive endoscopic surgery. However, foreign body or granulomatous reactions have been documented and should be considered prior to its use in otologic surgery.

[Effect of pH on the chelation between strontium ions and decellularized small intestinal submucosal sponge scaffolds].

OBJECTIVE: To investigate the preparation of decellularized small intestinal submucosa (dSIS) sponge scaffolds with chelated strontium (Sr) ions at different pH values, and to select the appropriate pH values for synthesizing Sr/dSIS scaffolds using the physicochemical properties and biocompatibility of the scaffolds as evaluation indexes. METHODS: (1) Sr/dSIS scaffolds preparation and grouping: After mixing dSIS solution and strontium chloride solution in equal volumes, adjusting pH of the solution to 3, 5, 7, and 9 respectively, porous scaffolds were prepared by freeze-drying method after full reaction at 37℃, which were named Sr/dSIS-3, -5, -7, and -9 respectively, and the dSIS scaffolds were used as the control group. (2) Physicochemical property evaluation: The bulk morphology of the scaffolds was observed in each group, the microscopic morphology analyzed by scanning electron microscopy, and the porosity and pore size determined, the surface elements analyzed by energy spectroscopy, the structure of functional groups analyzed by infrared spectroscopy, the chelation rate determined by atomic spectrophotometry, the water absorption rate detected by using specific gravity method, and the compression strength evaluated by universal mechanical testing machine.(3) Biocompatibility evaluation: The cytotoxicity and proliferative effect to bone mesenchymal stem cells (BMSCs) of each group were evaluated by Calcein-AM/PI double staining method. RESULTS: Scanning electron microscopy showed that the scaffolds of each group had an interconnected three-dimensional porous structure with no statistical difference in pore size and porosity. Energy spectrum analysis showed that strontium could be detected in Sr/dSIS-5, -7 and -9 groups, and strontium was uniformly distributed in the scaffolds. Functional group analysis further supported the formation of chelates in the Sr/dSIS-5, -7 and -9 groups. Chelation rate analysis showed that the Sr/dSIS-7 group had the highest strontium chelation rate, which was statistically different from the other groups (P < 0.05). The scaffolds in all the groups had good water absorption. The scaffolds in Sr/dSIS-5, -7 and -9 groups showed significantly improved mechanical properties compared with the control group (P < 0.05). The scaffolds in all the groups had good biocompatibility, and the Sr/dSIS-7 group showed the best proliferation of BMSCs. CONCLUSION: When pH was 7, the Sr/dSIS scaffolds showed the highest strontium chelation rate and the best proliferation effect of BMSCs, which was the ideal pH value for the preparation of the Sr/dSIS scaffolds.

Small intestinal submucosa xenograft to manage lower urinary tract prostheses perforation: a new path?

INTRODUCTION AND HYPOTHESIS: Tapes for stress urinary incontinence (SUI) and meshes for pelvic organ prolapse can result in postoperative complications, such as urethral (UP) or bladder (BP) perforations. Martius fat pad (MFP) is an historic procedure, widely used to treat lower urinary tract (LUT) fistulae. We report our experience with the insertion of the biological small intestinal submucosa (SIS) xenograft as an alternative to MFP in these prosthetic complications. METHODS: We conducted a retrospective, monocentric study which included all patients who underwent SIS insertion during surgical removal of tape/vaginal mesh for UP or BP from 2011 to 2019. Preoperative assessment was based on history, symptoms, physical examination and urethrocystoscopy. Primary outcome was successful repair defined as absence of any LUT defect. Secondary outcomes were complications, LUT symptoms, pain and additional SUI surgical procedures. RESULTS: Thirty-eight patients were included. Twenty-six had a UP and eight a BP. In four cases, perforation involved both the bladder neck and urethra. All LUT defects were cured. Six postoperative complications were reported (five of grade ≤ 2 and one of grade 3b according to the Clavien-Dindo classification). At the mean follow-up of 37.2 (range 6-98) months, 14 patients (36.8%) presenting a postoperative SUI underwent a SUI surgical procedure and 1 patient had a laparoscopic sacrocolpopexy for cystocele recurrence. CONCLUSION: Absorbable SIS xenograft is an effective and safe graft for the management of lower urinary tract tape and mesh perforations. The cost has to be balanced with the good results, short operative time and no fat pad complications as in MFP.

Porcine Small Intestinal Submucosa (SIS) as a Suitable Scaffold for the Creation of a Tissue-Engineered Urinary Conduit: Decellularization, Biomechanical and Biocompatibility Characterization Using New Approaches.

Bladder cancer (BC) is among the most common malignancies in the world and a relevant cause of cancer mortality. BC is one of the most frequent causes for bladder removal through radical cystectomy, the gold-standard treatment for localized muscle-invasive and some cases of high-risk, non-muscle-invasive bladder cancer. In order to restore urinary functionality, an autologous intestinal segment has to be used to create a urinary diversion. However, several complications are associated with bowel-tract removal, affecting patients' quality of life. The present study project aims to develop a bio-engineered material to simplify this surgical procedure, avoiding related surgical complications and improving patients' quality of life. The main novelty of such a therapeutic approach is the decellularization of a porcine small intestinal submucosa (SIS) conduit to replace the autologous intestinal segment currently used as urinary diversion after radical cystectomy, while avoiding an immune rejection. Here, we performed a preliminary evaluation of this acellular product by developing a novel decellularization process based on an environmentally friendly, mild detergent, i.e., Tergitol, to replace the recently declared toxic Triton X-100. Treatment efficacy was evaluated through histology, DNA, hydroxyproline and elastin quantification, mechanical and insufflation tests, two-photon microscopy, FTIR analysis, and cytocompatibility tests. The optimized decellularization protocol is effective in removing cells, including DNA content, from the porcine SIS, while preserving the integrity of the extracellular matrix despite an increase in stiffness. An effective sterilization protocol was found, and cytocompatibility of treated SIS was demonstrated from day 1 to day 7, during which human fibroblasts were able to increase in number and strongly organize along tissue fibres. Taken together, this in vitro study suggests that SIS is a suitable candidate for use in urinary diversions in place of autologous intestinal segments, considering the optimal results of decellularization and cell proliferation. Further efforts should be undertaken in order to improve SIS conduit patency and impermeability to realize a future viable substitute.

[Effects of different crosslinking treatments on the properties of decellularized small intestinal submucosa porous scaffolds].

OBJECTIVE: To compare the effects of three different crosslinkers on the biocompatibility, physical and chemical properties of decellularized small intestinal submucosa (SIS) porous scaffolds. METHODS: The SIS porous scaffolds were prepared by freeze-drying method and randomly divided into three groups, then crosslinked by glutaraldehyde (GA), 1-ethyl-3-(3-dimethylaminopropyl) carbodi-imide (EDC) and procyanidine (PA) respectively. To evaluate the physicochemical property of each sample in different groups, the following experiments were conducted. Macroscopic morphologies were observed and recorded. Microscopic morphologies of the scaffolds were observed using field emission scanning electron microscope (FESEM) and representative images were selected. Computer software (ImageJ) was used to calculate the pore size and porosity. The degree of crosslinking was determined by ninhydrin experiment. Collagenase degradation experiment was performed to assess the resistance of SIS scaffolds to enzyme degradation. To evaluate the mechanical properties, universal mechanical testing machine was used to determine the stress-strain curve and compression strength was calculated. Human bone marrow mesenchymal cells (hBMSCs) were cultured on the scaffolds after which cytotoxicity and cell proliferation were assessed. RESULTS: All the scaffolds remained intact after different crosslinking treatments. The FESEM images showed uniformed interconnected micro structures of scaffolds in different groups. The pore size of EDC group[(161.90±13.44) µm] was significantly higher than GA group [(149.50±14.65) µm] and PA group[(140.10±12.06) µm] (P < 0.05). The porosity of PA group (79.62%±1.14%) was significantly lower than EDC group (85.11%±1.71%) and GA group (84.83%±1.89%) (P < 0.05). PA group showed the highest degree of crosslinking whereas the lowest swelling ratio. There was a significant difference in the swelling ratio of the three groups (P < 0.05). Regarding to the collagenase degradation experiment, the scaffolds in PA group showed a significantly lower weight loss rate than the other groups after 7 days degradation. The weight loss rates of GA group were significantly higher than those of the other groups on day 15, whereas the PA group had the lowest rate after 10 days and 15 days degradation. PA group showed better mechanical properties than the other two groups. More living cells could be seen in PA and EDC groups after live/dead cell staining. Additionally, the proliferation rate of hBMCSs was faster in PA and EDC groups than in GA group. CONCLUSION: The scaffolds gained satisfying degree of crosslinking after three different crosslinking treatments. The samples after PA and EDC treatment had better physicochemical properties and biocompatibility compared with GA treatment. Crosslinking can be used as a promising and applicable method in the modification of SIS scaffolds.

Post-stapedotomy reparative granuloma following use of acellular porcine small intestinal submucosa.

PURPOSE: There have been multiple proposed etiologies of reparative granuloma following stapes surgery. In this report, we present the first case of post-stapedectomy reparative granuloma following the use of Biodesign (Cook Medical, Bloomington, IN) otologic graft material, an acellular matrix derived from porcine small intestinal submucosa, and review the literature of post-stapes surgery reparative granuloma. PATIENT: 50-year-old woman who developed a reparative granuloma following stapedotomy with acellular porcine intestinal submucosa presenting with profound hearing loss and vertigo. INTERVENTION: Middle ear exploration with excision of granuloma and revision stapedotomy. MAIN OUTCOME MEASURES: Audiologic outcomes as measured by pure-tone air and bone conduction thresholds and word recognition scores. Improvement in vertigo. MAIN FINDINGS: Surgical excision of the reparative granuloma with revision stapedotomy resolved vertigo. Hearing has improved progressively postoperatively. CONCLUSIONS: We report the first case of post-stapedotomy reparative granuloma following the use of acellular porcine intestinal submucosa. Although exact etiology cannot be determined from a single case report, this illustrates the need for careful use of novel foreign graft material. This case additionally confirms that removal of granuloma and inciting materials can salvage serviceable hearing.

Long-term follow-up of neurogenic bladder patients after bladder augmentation with small intestinal submucosa.

PURPOSE: To evaluate the long-term effect of using small intestinal submucosa (SIS) for bladder augmentation in patients with neurogenic bladder. MATERIALS AND METHODS: A total of 15 patients (age range 14-65 years; mean age 29.6 years) were enrolled in our study. The patients had poor bladder capacity and compliance caused by a neurogenic disorder requiring bladder augmentation. A small intestinal submucosa (SIS) cystoplasty was performed alone or in combination with ureter reimplantation. We prospectively followed the cohort to assess the urodynamics parameters, morphologic changes and patient satisfaction and evaluate the clinical benefit of the SIS procedure in long term. The surgical indications and complications were analyzed. RESULTS: The duration of follow-up ranged from 4.5 to 8.3 years (mean 6.3 years). Nine patients had expected long-term benefit, leading to an overall success rate of 60%. Two patients experienced immediate failure, and four patients slowed decrease in bladder capacity over time. Compared with the baseline data, there were significant increases in bladder capacity (163.5 ± 80.90-275.6 ± 159.5 ml, p < 0.05) and a significant decrease in maximum detrusor pressure (45.07 ± 29.03-17.60 ± 10.34 cmH2O, p < 0.05). Histologic examinations showed a complete conversion of SIS, leaving the urothelial lining and bladder wall containing muscular, vascular, and relatively thick connective tissue. Major complications included vesicoureteral reflux in five patients, bladder stone formation in one patient, and bladder perforation in one patient. CONCLUSION: Bladder augmentation with an SIS graft offers a partial long-term success rate in neurogenic bladder patients. This procedure cannot be recommended as a substitute for enterocystoplasty, especially in patients with severe upper urinary tract deterioration and/or bladder fibrosis.

[Preparation and osteogenic effect study of small intestinal submucosa sponge].

OBJECTIVE: To prepare and evaluate the basic properties in vitro of a novel small intestinal submucosa (SIS) sponge, and to describe the bone formation ability of the SIS sponge in vivo. METHODS: The SIS sponge was prepared by freeze-drying method. To evaluate the physicochemical properties of the sponge, electron microscope observation, porosity test, water absorption ability and mechanical property were conducted in vitro. The cytotoxicity of the SIS sponge was performed by cell counting kit-8 method. In vivo experiments, eighteen extraction sockets of premolar of three Beagle dogs were randomly divided into three groups: SIS sponge group (SIS sponge), positive control group (Bio-Oss granules and Bio-Gide membrane) and control group(no treatment). The animals were sacrificed 4 weeks and 12 weeks after operation, and micro computed tomography (Micro-CT) was applied to measure the bone volume fraction (BV/TV) and bone mineralized density (BMD). The data were analyzed with one-way ANOVA. RESULTS: The average pore diameter of the SIS sponge was (194.90±30.39) µm, the porosity was 92.31%±0.24%, the water absorption rate was 771.50%±40.90%, and the compressive elastic modulus was (2.20±0.19) kPa. There was no significant difference in cell proliferation ability between SIS sponge and control group (P>0.05). Micro-CT quantitative results showed that BV/TV of SIS sponge group (52.81%±3.21%) and positive control group (58.30%±9.36%) were significantly higher than that of control group (38.65%±4.80%) 4 weeks after operation (P < 0.05). The BMD of SIS sponge group [(887.09±61.02) mg/cm3], positive control group [(952.05±132.78) mg/cm3] and control group [(879.29±74.27) mg/cm3] showed no statistical difference 4 weeks after operation (P>0.05). The BV/TV of positive control group (60.57%± 6.56%) was significantly higher than that of SIS sponge group (47.89%±3.59%) and control group (42.99%±2.54%) 12 weeks after operation (P < 0.05). BMD of SIS sponge group [(1047±89.95) mg/cm3] and positive control group [(1101.37±98.85) mg/cm3] were significantly higher than that of control group [(890.36±79.79) mg/cm3] 12 weeks after operation (P < 0.05). CONCLUSION: The SIS sponge has satisfying physicochemical properties and biocompatibility. The SIS sponge significantly increased bone volume fraction in the early stage of bone formation (4 weeks) and bone mineralized density in the late stage of bone formation (12 weeks).

[Biodegradation properties of multi-laminated small intestinal submucosa].

OBJECTIVE: To study the biodegradation properties of multi-laminated small intestinal submucosa (mSIS) through in vitro and in vivo experiments, comparing with Bio-Gide, the most widely used collagen membrane in guided bone regeneration (GBR) technique, for the purpose of providing basis to investigate whether mSIS meets the requirements of GBR in dental clinics. METHODS: The degradation properties were evaluated in vitro and in vivo. In vitro degradation was performed using prepared collagenase solution. Morphology of mSIS and Bio-Gide in degradation solution were observed and the degradation rate was calculated at different time points. In in vivo experiments, nine New Zealand rabbits were used for subcutaneous implantation and were divided into three groups according to observation intervals. Six unconnected subcutaneous pouches were made on the back of each animal and were embedded with mSIS and Bio-Gide respectively. At the end of weeks 4, 8, and 12 after operation, gross observation and HE staining were used to evaluate the degree of degradation and histocompatibility. RESULTS: In vitro degradation experiments showed that mSIS membrane was completely degraded at the end of 12 days, while Bio-Gide was degraded at the end of 7 days. Besides, mSIS maintained its shape for longer time in the degradation solution than Bio-Gide, indicating that mSIS possessed longer degradation time, and had better ability to maintain space than Bio-Gide. In vivo biodegradation indicated that after 4 weeks of implantation, mSIS remained intact. Microscopic observation showed that collagen fibers were continuous with a few inflammatory cells that infiltrated around the membrane. Bio-Gide was basically intact and partially adhered with the surrounding tissues. HE staining showed that collagen fibers were partly fused with surrounding tissues with a small amount of inflammatory cells that infiltrated as well. Eight weeks after operation, mSIS was still intact, and was partly integrated with connective tissues, whereas Bio-Gide membrane was mostly broken and only a few residual fibers could be found under microscope. Only a small amount of mSIS debris could be observed 12 weeks after surgery, and Bio-Gide could hardly be found by naked eye and microscopic observation at the same time. CONCLUSION: In vitro degradation time of mSIS is longer than that of Bio-Gide, and the space-maintenance ability of mSIS is better. The in vivo biodegradation time of subcutaneous implantation of mSIS is about 12 weeks and Bio-Gide is about 8 weeks, both of which possess good biocompatibility.