Immobilizing c(RGDfc) on the surface of metal-phenolic networks by thiol-click reaction for accelerating osteointegration of implant.

The limited osteointegration often leads to the failure of implant, which can be improved by fixing bioactive molecules onto the surface, such as arginyl-glycyl-aspartic acid (RGD): a cell adhesion motif. Metal-Phenolic Networks (MPNs) have garnered increasing attention from different disciplines in recent years due to their simple and rapid process for depositing on various substrates or particles with different shapes. However, the lack of cellular binding sites on MPNs greatly blocks its application in tissue engineering. In this study, we present a facile and efficient approach for producing PC/Fe@c(RGDfc) composite coatings through the conjugation of c(RGDfc) peptides onto the surface of PC/Fe-MPNs utilizing thiol-click reaction. By combined various techniques (ellipsometry, X-ray photoelectron spectroscopy, Liquid Chromatography-Mass Spectrometry, water contact angle, scanning electronic microscopy, atomic force microscopy) the physicochemical properties (composition, coating mechanism and process, modulus and hydrophilicity) of PC/Fe@c(RGDfc) surface were characterized in detail. In addition, the PC/Fe@c(RGDfc) coating exhibits the remarkable ability to positively modulate cellular attachment, proliferation, migration and promoted bone-implant integration in vivo, maintaining the inherent features of MPNs: anti-inflammatory, anti-oxidative properties, as well as multiple substrate deposition. This work contributes to engineering MPNs-based coatings with bioactive molecules by a facile and efficient thiol-click reaction, as an innovative perspective for future development of surface modification of implant materials.

Facile strategy for gelatin-based hydrogel with multifunctionalities to remodel wound microenvironment and accelerate healing of acute and diabetic wounds.

Chronic diabetic wounds represent the most common diabetes complication. Wound healing depends on scavenging reactive oxygen species (ROS), neovascularization, and controlling infection. A naturally derived gelatin-based hydrogel is biocompatible, biodegradable, does not promote inflammation, and can remove ROS, but strategies for developing a gelatin-based hydrogel currently require careful chemical modification of gelatin and time-consuming purification and post-crosslinking processing. Herein, a facile method of combining zirconium (Zr4+), gelatin, and quercetin (QCN) to generate an injectable gelatin-based hydrogel (QCN@Gel-Zr) for diabetic wound treatment was presented. Adding QCN improved the mechanical, injection, and adhesive performance of the Gel-Zr hydrogel and conferred antibacterial and free radical-scavenging abilities. These properties induced cellular proliferation and migration, protection against oxidative stress, and reduction in inflammatory expression. In vivo models of acute and chronic diabetic skin wounds were used to demonstrate biocompatibility and the ability of the gelatin hydrogels to promote wound healing. The histological analysis showed that the QCN@Gel-Zr hydrogel promoted angiogenesis, collagen deposition, and hair follicle regeneration with no detectable cytotoxicity. This study demonstrates the preparation of gelatin-based hydrogel with various flexible functions to address the complex biological requirements of diabetic wound repair.

Facile General Injectable Gelatin/Metal/Tea Polyphenol Double Nanonetworks Remodel Wound Microenvironment and Accelerate Healing.

Treating the most widespread complication of diabetes: diabetic wounds poses a significant clinical obstacle due to the intricate nature of wound healing in individuals with diabetes. Here a novel approach is proposed using easily applicable injectable gelatin/metal/tea polyphenol double nanonetworks, which effectively remodel the wound microenvironment and accelerates the healing process. The gelatin(Gel) crosslink with metal ions (Zr4+ ) through the amino acids, imparting advantageous mechanical properties like self-healing, injectability, and adhesion. The nanonetwork's biological functions are further enhanced by incorporating the tea polyphenol metal nanonetwork through in situ doping of the epigallocatechin gallate (EGCG) with great antibacterial, self-healing, antioxidant, and anticancer capabilities. The in vitro and in vivo tests show that this double nanonetworks hydrogel exhibits faster cell migration and favorable anti-inflammatory and antioxidant properties and can greatly reshape the microenvironment of diabetic wounds and accelerate the wound healing rate. In addition, this hydrogel is completely degraded after subcutaneous injection for 7 days, with nondetectable cytotoxicity in H&E staining of major mice organs and the serum level of liver function indicators. Considering the above-mentioned merits of this hydrogel, it is believed that the injectable gelatin/metal/tea polyphenol double nanonetworks have broad biomedical potential, especially in diabetic wound repair and tissue engineering.

Physical Properties of the Second Type of Aciniform Spidroin (AcSp2) from Neoscona theisi Reveal a pH-Dependent Self-Assembly Repetitive Domain.

Orb-weaving spiders can use an array of specialized silks with diverse mechanical properties and functions for daily survival. Of all spider silk types, aciniform silk is the toughest silk fiber that combines high strength and elasticity. Although aciniform spidroins (AcSp) are the main protein in aciniform silks, their complete genes have rarely been characterized until now. Moreover, the structural and physical properties of AcSp variant proteins within the species are also unclear. Here, we present three full-length AcSp genes (named AcSp1A, AcSp1B, and AcSp2) from the orb-weaving spider Neoscona theisi and investigate the structural and mechanical features of these three AcSp repetitive domains. We demonstrate that all three AcSp proteins have mainly α-helical structural features in neutral solution and high thermal stability. Significantly, the AcSp2 repetitive domain shows a pH-dependent structural transition from α to ß conformations and can self-assemble into amyloid fibrils under acidic conditions, which is the first reported AcSp repetitive domain with pH-dependent self-assembly capacity. Compared with the other two AcSp spidroins, AcSp2 demonstrated the lowest expression level in the aciniform gland but had the highest strength for its silk fiber. Collectively, our findings provide new insight into the physical properties of each component of aciniform silk and expand the repertoire of known spidroin sequences for the synthesis of artificial silk materials.

Subtle distinction in molecular structure of flavonoids leads to vastly different coating efficiency and mechanism of metal-polyphenol networks with excellent antioxidant activities.

Metal-polyphenol networks (MPNs) are of immense scientific interest because of their simple and rapid process to deposit on various substrates or particles with different shapes. However, there are rare reports on the effect of polyphenol molecular structure on coating efficiency and mechanism of MPNs. Herein, three typical flavonoid polyphenols, catechin (Cat), epigallocatechin (EGC) and procyanidin (PC), with the same skeleton (C6-C3-C6) but subtle distinction in molecular structure, were selected to build MPN coatings with ferric ions (Fe3+). And various techniques combined with the density functional theory (DFT) were applied to deeply reveal the roles of coordinative phenolic hydroxyl groups as well as noncovalent interactions (hydrogen bonding and π - π stacking) in the formation of flavonoid-based MPNs. We found that more accessible numbers of coordinative phenolic hydroxyl groups, the higher coating efficiency. In these flavonoid-based MPNs, the single-complex is the predominant during the coordinative modes between phenolic hydroxyl and Fe3+, not the previously reported mono-complex, bis-complex and/or tris-complex. Besides coordinative interaction, noncovalent interactions also contribute to MPNs formation, and hydrogen bonds prevail in the noncovalent interaction compared with π-π stacking. And these engineered MPN coatings can endow the substrate with excellent antioxidant activities. This study contributes to in-depth understanding the building mechanism of flavonoid-based MPNs, and increasing coating efficiency by choosing proper polyphenols.

pH-Responsive Hexa-Histidine Metal Assembly (HmA) with Enhanced Biocatalytic Cascades as the Vehicle for Glucose-Mediated Long-Acting Insulin Delivery.

Diabetes has been listed as one of the three major diseases that endanger human health. Accurately injecting insulin (Ins) depending on the level of blood glucose (LBG) is the standard treatment, especially controlling LBG in the long-term by a single injection. Herein, the pH-responsive hexa-histidine metal assembly (HmA) encapsulated with enzymes (GOx and CAT) and Ins (HmA@GCI) is engineered as the vehicle for glucose-mediated insulin delivery. HmA not only shows high proteins loading efficiency, but also well retained proteins activity and protect proteins from protease damage. Within HmA, the biocatalytic activities of enzymes and the efficiency of the cascade reaction between GOx and CAT are enhanced, leading to a super response to the change of LBG with insulin release and efficient clearance of harmful byproducts of GOx (H2 O2 ). In the treatment of diabetic mice, HmA@GCI reduces LBG to normal in half an hour and maintains for more than 5 days by a single subcutaneous injection, and nearly 24 days with four consecutive injections. During the test period, no symptoms of hypoglycemia and toxicity to tissues and organs are observed. These results indicate that HmA@GCI is a safe and long-acting hypoglycemic agent with prospective clinical application.

Hydrazone-Based Amphiphilic Brush Polymer for Fast Endocytosis and ROS-Active Drug Release.

Due to the high reactivity of reactive oxygen species (ROS), it is essential to sweep them away in time. In this study, ClO--responsible amphiphilic brush polymers were prepared by free radical polymerization using two monomers consisting of polyethylene glycol as the hydrophilic part, and an alkyl chain connected by hydrazone as the hydrophobic part. The macromolecules assemble into particles with nanoscaled dimensions in a neutral buffer, which ensures quick cellular internalization. The polymer has a low critical micellization concentration and can encapsulate hydrophobic drug molecules up to 19% wt. The micelles formed by the polymer disassemble in a ClO--rich environment and release 80% of their cargo within 2 h, which possesses a faster release rate compared to the previous systems. The relatively small size and the quick response of hydrazone toward ClO- ensure a quick uptake and elimination of ROS in vitro and in vivo.

Transformation of the shape and shrinking the size of acid-resistant metal-organic frameworks (MOFs) for use as the vehicle of oral proteins.

The oral delivery of protein-based drugs is of great significance, but faces various obstacles, including the deactivation of proteins by the low pH in the stomach and the high concentration of protease, poor transport through intestinal bio-barriers, etc. Herein, we present an acid-resistant metal-organic framework (MOF), NU-1000, in which insulin (Ins, a model protein) was loaded with high capacity (Ins@NU-1000) through the pseudo second-order kinetic model and Langmuir isotherm model. Ins@NU-1000 protects Ins from deactivation in the stomach acid environment and releases it in the intestine through the transformation of the micro-sized rod particles into spherical nanoparticles. Interestingly, the rod particles exhibit long-term retention in the intestine, and Ins is efficiently transported by the shrunk nanoparticles through intestinal bio-barriers and released into the blood, resulting in significant oral hypoglycemic effects (lasting more than 16 h after a single oral administration). Our findings demonstrate that switching the physical properties of the delivery vehicle, such as the shape and size, can contribute to the success of oral protein administration.

Lean adipose tissue macrophage derived exosome confers immunoregulation to improve wound healing in diabetes.

Chronic non-healing wounds, a prevalent complication of diabetes, are associated with increased mortality in diabetic patients. Excessive accumulation of M1 macrophages in diabetic wounds promotes inflammation and results in dysregulated tissue repair. Adipose tissue macrophages (ATMs) derived from healthy lean donors have the ability to improve glucose tolerance and insulin sensitivity, as well as modulate inflammation. MicroRNAs (miRs), which can be packaged into exosomes (Exos) and secreted from cells, serve as essential regulators of macrophage polarization. Here, we revealed that ATMs isolated from lean mice secrete miRs-containing Exos, which modulate macrophage polarization and promote rapid diabetic wound healing when administered to diabetes-prone db/db mice. The miRs sequence of tissue samples from wounds treated with Exos secreted by lean ATMs (ExosLean) revealed that miR-222-3p was up-regulated. Further analyses showed that inhibiting miR-222-3p using a miR inhibitor impaired the macrophage-reprogramming effect of ExosLean. In the excisional skin wound mouse model, locally inhibiting miR-222-3p disrupted healing dynamics and failed to modulate macrophage polarization. Mechanistic studies revealed a connection between miR-222-3p, Bcl2l11/Bim, an inflammatory response effector, macrophage polarization, and diabetic wound healing. In summary, ExosLean act as positive regulators of macrophage polarization by regulating miR levels in wounds and accelerating wound healing, and thus have important implications for wound management in diabetes.

Role of Driving Force on Engineering Layer-by-Layer Protein/Polyphenol Coating with Flexible Structures and Properties.

Protein-based coatings are of immense interest due to their rich biological functions. Layer-by-layer (LbL) assembly, as a powerful means of transferring protein functions to the material surface, has received widespread attention. However, the assembly mechanism of protein-based LbL coatings is still far from being explained, not only because of protein structure and function diversity but also characterization limitations. Herein, we monitored in situ the LbL assembly process of tannic acid (TA) and lysozyme (Lyz), a classic pair of polyphenol and protein, by combining quartz crystal microbalance with dissipation monitoring (QCM-D) and spectroscopic ellipsometry (SE). The water content, morphology, mechanical properties, antioxidant activity, and the driving force of TA-Lyz coating engineered under different pH values were analyzed in detail by various techniques. The water content, a key factor in TA-Lyz coatings, increased with increasing assembled pH values, which resulted in a porous morphology, inhomogeneous mechanical distribution, faster assembly growth, and better antioxidant activity in both acellular and cellular levels. In addition, high water content is unfavorable to both entropy and enthalpy changes, and the thermodynamic driving force of TA and Lyz assembly mainly comes from the enthalpy change brought by the noncovalent interaction between TA and Lyz. These results provide new insights into engineering the structure, function, and assembly mechanisms of protein-based coatings.

Negative-pressure wound therapy (NPWT) for the treatment of pacemaker pocket infection in patients unable or unwilling to undergo CIED extraction.

PURPOSE: The occurrence of cardiac pacemaker pocket infection has markedly increased and has become a new problem facing cardiovascular internists. The aim of our study was to investigate the effectiveness and safety of treating cardiac pacemaker pocket infection using negative-pressure wound therapy (NPWT) in patients who are unwilling or unable to have their cardiac implantable electronic devices (CIEDs) removed. METHODS: From March 2013 to April 2019, NPWT was applied to 26 patients with cardiac pacemaker pocket infection who were unwilling or unable to have their CIEDs removed. In the first stage, a negative-pressure drainage system was placed in the pacemaker pocket after debridement. Then, NPWT was used to seal the wound, and the negative pressure (300-400 mmHg) was sustained for 5-7 days. In the second stage, the pacemaker was relocated to the subpectoral layer, and the wound was closed. RESULTS: In all but three of our 26 patients, the wound healed completely without complications and without evidence of residual infection. The average follow-up period was 26.92 ± 9.46 months. Only 3 diabetic patients whose tissue bacterial cultures revealed that methicillin-resistant Staphylococcus epidermidis developed uncontrolled infections. Eventually, the entire original pacemaker systems were removed, and new pacemakers were implanted in the contralateral chest wall. CONCLUSIONS: When warranted by strictly selected indications, the method of NPWT without CIED extraction can be considered as a new and effective treatment for patients with pacemaker pocket infection who are unwilling or unable to have the device removed.

[Experimental study on the effect of desferrioxamine on targeted homing and angiogenesis of bone marrow mesenchymal stem cells].

Objective: To investigate whether desferrioxamine (DFO) can enhance the homing of bone marrow mesenchymal stem cells (BMSCs) and improve neovascularization in random flaps of rats. Methods: BMSCs and fibroblasts (FB) of luciferase transgenic Lewis rats were isolated and cultured. Forty 4-week-old Lewis male rats were used to form a 10 cm×3 cm rectangular flap on their back. The experimental animals were randomly divided into 4 groups with 10 rats in each group: in group A, 200 µL PBS were injected through retrobulbar venous plexus; in group B, 200 µL FB with a concentration of 1×10 6 cells/mL were injected; in group C, 200 µL BMSCs with a concentration of 1×10 6 cells/mL were injected; in group D, cells transplantation was the same as that in group C, after cells transplantation, DFO [100 mg/(kg·d)] were injected intraperitoneally for 7 days. On the 7th day after operation, the survival rate of flaps in each group was observed and calculated; the blood perfusion was observed by laser speckle imaging. Bioluminescence imaging was used to detect the distribution of transplanted cells in rats at 30 minutes and 1, 4, 7, and 14 days after operation. Immunofluorescence staining was performed at 7 days after operation to observe CD31 staining and count capillary density under 200-fold visual field and to detect the expressions of stromal cell derived factor 1 (SDF-1), epidermal growth factor (EGF), fibroblast growth factor (FGF), and Ki67. Transplanted BMSCs were labeled with luciferase antibody and observed by immunofluorescence staining whether they participated in the repair of injured tissues. Results: The necrosis boundary of ischemic flaps in each group was clear at 7 days after operation. The survival rate of flaps in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). Laser speckle imaging showed that the blood perfusion units of flaps in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). Bioluminescence imaging showed that BMSCs gradually migrated to the ischemia and hypoxia area and eventually distributed to the ischemic tissues. The photon signal of group D was significantly stronger than that of other groups at 14 days after operation ( P<0.05). CD31 immunofluorescence staining showed that capillary density in groups C and D was significantly higher than that in groups A and B, and in group D than in group C ( P<0.05). The expressions of SDF-1, EGF, FGF, and Ki67 in groups C and D were significantly stronger than those in groups A and B, and in group D than in group C. Luciferase-labeled BMSCs were expressed in the elastic layer of arteries, capillaries, and hair follicles at 7 days after transplantation. Conclusion: DFO can enhance the migration and homing of BMSCs to the hypoxic area of random flap, accelerate the differentiation of BMSCs in ischemic tissue, and improve the neovascularization of ischemic tissue.

Development of a Highly Specific Fluorescence Immunoassay for Detection of Diisobutyl Phthalate in Edible Oil Samples.

The diisobutyl phthalate (DiBP) hapten containing an amino group was synthesized successfully, and the polyclonal antibody against 4-amino phthalate-bovine serum albumin (BSA) was developed. On the basis of the polyclonal antibody, a rapid and sensitive indirect competitive fluorescence immunoassay (icFIA) has been established to detect DiBP in edible oil samples for the first time. Under the optimized conditions, the quantitative working range of the icFIA was from 10.47 to 357.06 ng/mL (R(2) = 0.991), exhibiting a detection limit of 5.82 ng/mL. In this assay, the specific results showed that other similar phthalates did not significantly interfere with the analysis, with the cross-reactivity less than 1.5%, except for that of DiBAP. Thereafter, DiBP contamination in edible oil samples was detected by icFIA, with the recovery being from 79 to 103%. Furthermore, the reliability of icFIA was validated by gas chromatography-mass spectrometry (GC-MS). Therefore, the developed icFIA is suitable for monitoring DiBP in some edible oil samples.

Preservation of canine composite facial flaps using UW solution.

OBJECTIVE: To evaluate the effect of University of Wisconsin (UW) solution on composite facial flaps in dogs to offer a preservation time limit for clinical application. METHODS: The experiment included 2 parts. In part 1, 32 half facial flaps were cold stored for 12, 24, 36, and 48 hours in UW solution (experimental group) or normal saline (control group). In part 2, 8 flaps that had been cold stored in UW solution for 24 (group A, n = 3), 36 (group B, n = 3), and 48(group C, n = 2) hours were autotransplanted. RESULTS: After preservation in part 1, the viability of each tissue type (skin, mucosa, muscle, blood vessel, nerve, and gland) in the experimental groups was better than that in the control group. Muscle viability decreased more quickly than did the viability of other tissue. In the experimental groups, the viability of all tissue preserved for 12 and 24 hours was better than that of tissue preserved for 36 and 48 hours. After 48 hours of preservation, tissue had good structure and integrity in the experimental group but showed degeneration in the control group. In part 2, the flap survival percentages were 100%, 100%, and 99.7% in group A; 93.2%, 95.7%, and 94.1% in group B; and 87.2% and 86.1% in group C. Six months after surgery, the dogs in group A showed contraction potential and corneal reflex. CONCLUSION: Twenty-four hours could be considered a reference time for clinical application of UW solution flap preservation.

Transplanted endothelial progenitor cells increase neo-vascularisation of rat pre-fabricated flaps.

BACKGROUND: Flap pre-fabrication is dependent on the eventual re-vascularisation of the implanted vascular carrier and the presence of a desirable, donor-skin site. However, insufficient neo-vascularisation and subsequent necrosis is an obstacle for this technique. A recent discovery demonstrated that endothelial progenitor cells (EPCs) augment post-natal neo-vascularisation in ischaemic tissues. As a result, we examined whether transplantation of bone-marrow-derived EPCs (BM-EPCs) increases neo-vascularisation and augments the survival areas of pre-fabricated flap in a rat model. METHODS: Rat bone-marrow-derived mononuclear cells (BM-MNCs) were isolated by density gradient centrifugation and cultured in EGM-2MV. The EPCs derived from BM-MNCs were identified by surface makers such as CD34, KDR, CD133 and double-positive staining with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labelled acetylated low-density lipoprotein (Dil-Ac-LDL) and FITC-labelled Ulex europaeus agglutinin-1 (FITC-UEA-1). Pre-fabricated flaps were created by ligating the right femoral vascular pedicle and implanting it underneath the abdominal flap. Forty-five rats were randomly divided into three equal groups. The implantation site around the pedicle was injected subcutaneously with fluorescence-labelled BM-EPCs in group I (n=15), with vascular endothelium growth factor (VEGF) protein in group II (n=15) and with phosphate-buffered saline (PBS) in control group III. Four weeks after injection, the abdominal island flap was elevated and sutured back. Then, neo-vascularisation and flap viability was evaluated on day 7. The labelled EPCs were examined by fluorescence microscopy. RESULTS: After 7 days of culture, the attached cells were spindle shaped and expressed CD34, KDR and CD133. These cells incorporated DiI-Ac-LDL and bound FITC-UEA-1. Greater augmentation of flap survival (87.26+/-10.13% vs. 66.13+/-9.9% and 55.59+/-13.06%, P<0.001), higher capillary density (38.67+/-9.52 capillaries per mm(2) vs. 25.83+/-6.34 capillaries per mm(2) and 26.5+/-5.61 capillaries per mm(2), P<0.05) and larger vascular territories on the microangiogram were observed in the EPCs-treated group relative to the other two groups. The labelled cells formed new vessel structures and expressed von Willebrand factor (vWF) in the pre-fabricated flap. CONCLUSIONS: Local transplantation of BM-EPCs may be a useful strategy for increasing the survival of pre-fabricated flaps, which is consistent with 'therapeutic vasculogenesis'. EPCs are superior to VEGF in their neo-vascularisation ability.

Autologous fat grafting to the breast for cosmetic enhancement: experience in 66 patients with long-term follow up.

BACKGROUND: Autologous fat grafting to the breast for cosmetic enhancement remains controversial because the efficacy and fate of fat grafting to the breast are primarily unknown. In this report, we present our retrospective study in 66 patients who underwent autologous fat grafting to the breast for various cosmetic reasons and who were followed with sonography, mammography, or magnetic resonance imaging (MRI). METHODS: Sixty-six patients who desired cosmetic enhancement of the breast for various reasons underwent autologous fat transplantation between August 2000 and March 2005 in our institution. The cosmetic outcome was assessed by the plastic surgeons as well as the patients. The imaging features of fat necrosis, cyst formation, and calcification in these patients were carefully studied and biopsies of palpable lumps were evaluated histologically. RESULTS: All patients were followed from 13 to 61 months with an average of 37 months. Breast cosmetic contour was significantly improved in 28 patients (42.4%), improved in 24 patients (36.4%), and not improved in 14 patients (21.2%) as judged by the plastic surgeons. Twenty-seven patients (40.9%) were very satisfied, 26 patients (39.4%) were satisfied, and 13 patients (19.7%) were unsatisfied. Eleven patients (16.7%) developed liponecrotic cysts but only two patients elected to have the breast lump surgically removed. CONCLUSION: Autologous fat grafting to the breast can be a useful procedure for cosmetic enhancement in many patients who desire such a procedure. Patients with breast contour deformities after removal of silicon implants were found to be the best candidates for fat grafting. The primary long-term complication is the formation of liponecrotic cysts which have characteristically benign appearances in sonography, mammography or MRI.

[Anatomic study of supratrochlear artery and its application in nasal reconstruction].

OBJECTIVE: To study the anatomy of the cutaneous branch (CB) of supratrochlear artery and its relevance to the design of frontal flap in nasal reconstruction. METHODS: 10 fresh cadavers were dissected to study the position and course of the CB of supratrochlear artery (supraorbital rim and facial midline as landmark). The communication between the CB and supraorbital artery was also studied. 5 cases of ultra-thin frontal flaps and 11 cases of bi-flap( cutaneous flap and muscular flap) were designed on anatomic basis. The survival rate of flap, the stability and aesthetic appearance of the reconstructed nose were followed up. RESULTS: The supratrochlear artery gave off constant CB (1.18 +/- 0.36) cm from upper orbital rim and (1.35 +/- 0.34) cm from the midline of face. The CB passed in a subcutaneous plane and communicated with the bilateral muscular branch, CB of the opposite side and bilateral supraorbital artery. The supratrochlear artery only had CB with no muscular branch in 3 cases. All the flaps survived completely except one with blister on the nose tip which healed spontaneously. The postoperative aesthetic appearance was very satisfactory. CONCLUSIONS: The supratrochlear artery has constant CB. The frontal ultra-thin flap pedicled with the CB can improve the therapeutic effect of nasal reconstruction.

[Strategy study of harvesting total facial flap and donor choice for allograft transplantation in cadaver].

OBJECTIVE: To explore the operational strategy of harvesting total facial allograft by autopsy. METHODS: Twelve fresh human cadavers were dissected. They were divided into two groups randomly. The total facial-scalp flap of the group I was elevated by the bi-pedicle method, the group II was operated with single-pedicle method. Both were dissected at the deep plane of the SMAS. : the time of facial flap harvesting, length of the artery vein and nerve pedicles of the donor were measured and marked, after operation, in each group we transferred one facial allograft to another. Then the free graft of group I was poured through artery by methylthioninium chloride to study vascular territories. RESULTS: Mean harvesting time of the group I (46 +/- 11) minutes, group II (111 +/- 7) minutes, P < 0.01. Perfusion result shows that unilateral superficial temporal artery and the opposite side of the facial artery can supply blood for whole face. The pedicle was long enough for anastomosis. Post-operation appearance: the face looks like neither the donor nor the recipient primarily, It's mainly due to the characteristics of the skeleton and the soft tissues. CONCLUSIONS: The bi-pedicle method of the harvesting total facial allograft is concise, fast, safe can be widely applied in clinical.

[Research of the preservation of the composite facial allograft].

OBJECTIVE: To investigate the effective method of preserving composite facial allograft so as to attenuate ischemic injury. METHODS: The composite facial allografts were harvested from dog, perfused and preserved with 4 degrees C physiological sodium chloride and UW solution respectively. Immediately after the removal of the flap, after 12, 24, 48 h of preservation, MTT assay was used to determine the viability of several kinds of tissue, including skin, mucosa, muscle, bleed vessel, nerve and gland. The results of the two groups were compared in term of viability percentage. The pathology of several tissues were observed after 24 and 48 h of storage. RESULTS: The viability percentage of every tissue conserved in UW solution for 48 hours was more than 75%. There was significant difference between physiological sodium chloride group and UW group (P < 0.05). Some changes, including Porous arrangement of fibers in connective tissue of skin and mucosa, hyalinization of tissue around the hair follicle and edema of cell in hair follicle, enlargement of space between muscle bundles and unclearness of boundary of acinus could be seen in physiological sodium chloride group while no significant change in UW group. CONCLUSIONS: UW solution could be considered as preservation solution for composite facial allograft.

[Establishment of composite facial and scalp allograft transplantation model in canine].

OBJECTIVE: To develop an experimental model of composite facial and scalp allograft in canine in order to investigate technical and immunological aspects and functional recovery of facial muscles of this new approach to facial reconstruction. METHODS: (1) Anatomic study: Four mongrel dogs were used for anatomical dissection of the head and neck region and for harvesting flap experiment. (2) Autologous transplantation (group I): Three types composite facial and scalp autologous transplantation were performed in five mongrel dogs. Type I composite tissue flap (group I a n = 2) included bilateral external ear and orbicularis oculi muscle. Type II (group I b n = 1) included single-lateral external ear, orbicularis oculi muscle, external nose upper and lower lip. Type III (group I c n = 2) included single - lateral external ear and orbicularis oculi muscle. (3) Allograft transplantation (group II): In group II a (n = 2), two allograft transplantation were performed with type III composite facial and scalp . In group II b (n = 4), four allograft transplantation were performed with the modified type III composite facial and scalp which included single - lateral external ear, orbicularis oculi muscle and one third of inferior tarsal plate and palpebral conjunctiva. To prevent allograft rejection, Cyclosporin A (CsA) and Methylprednisolone (MP) or Prednisone (PS ) were combined used as immunosuppressive protocol . Dose of CsA was adjusted depending on its blood drug level. Electromyogram (EMG) of orbicularis oculi muscle was carried out at 4 weeks, 6 weeks, 12 weeks and 6 months postoperation. RESULTS: (1) The facial anatomic characteristic of dog is similar to that of human being, external carotid artery and external jugular vein afford good blood supply to composite facial and scalp. (2) The dogs in group I c were long-term surviving with leakage of salivary juice. (3) In group II a (n = 2), one dog presented rejection reaction at 28th day postoperation, the reversal of rejection was achieved by increasing the dose of CsA and prednisone and with topical clobetasol for 2 weeks, the dog survived indefinitely( > 309 days). In group II b (n = 4), there were three dogs survived indefinitely ( > 159 days, > 129 days, > 108 days) without complication, EMG showed the function of orbicularis oculi muscle was gradually improving. CONCLUSION: The modified type III composite facial and scalp allograft transplantation model is an ideal model for facial allograft transplantation study.