Construction of multifunctional coating with cationic amino acid-coupled peptides for osseointegration of implants.

Osseointegration is an important indicator of implant success. This process can be improved by coating modified bioactive molecules with multiple functions on the surface of implants. Herein, a simple multifunctional coating that could effectively improve osseointegration was prepared through layer-by-layer self-assembly of cationic amino acids and tannic acid (TA), a negatively charged molecule. Osteogenic growth peptide (OGP) and the arginine-glycine-aspartic acid (RGD) functional polypeptides were coupled with Lys6 (K6), the two polypeptides then self-assembled with TA layer by layer to form a composite film, (TA-OGP@RGD)n. The surface morphology and biomechanical properties of the coating were analyzed in gas and liquid phases, and the deposition process and kinetics of the two peptides onto TA were monitored using a quartz crystal microbalance. In addition, the feeding consistency and adsorption ratios of the two peptides were explored by using fluorescence visualization and quantification. The (TA-OGP@RGD)n composite membrane mediated the early migration and adhesion of cells and significantly promoted osteogenic differentiation and mineralization of the extracellular matrix in vitro. Additionally, the bifunctional peptide exhibited excellent osteogenesis and osseointegration owing to the synergistic effect of the OGP and RGD peptides in vivo. Simultaneously, the (TA-OGP@RGD)n membrane regulated the balance of reactive oxygen species in the cell growth environment, thereby influencing the complex biological process of osseointegration. Thus, the results of this study provide a novel perspective for constructing multifunctional coatings for implants and has considerable application potential in orthopedics and dentistry.

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.

Cadaveric comparison of two facial flap-harvesting techniques for alloplastic facial transplantation.

BACKGROUND: Functional and aesthetic reconstruction of severe facial deformities presents a major challenge, and the results are rarely satisfactory. Recent clinical success of composite tissue allograft transplantation and improvements in autoimmune regulation have initiated efforts to reconstruct severe facial deformities with alloplastic tissue. Few reports address the full facial flap dissection approach, where lengthy procedural times remain a limiting factor in achieving optimal graft survival. Extensive vascular anastomoses within facial tissues provide a unique opportunity to explore alternative graft harvesting strategies to optimise operative ischaemia. OBJECTIVE: The aim of the study was to shorten donor-graft harvesting time and reduce warm ischaemia. We evaluated alternative facial harvesting strategies through mock cadaveric facial transplantations. METHODS: Cadaveric dissections were performed to explore facial-scalp reconstruction alternatives. Six paired sub-superficial muscloaponeurotic system (SMAS) plane composite facial-scalp flaps were harvested using either a superficial temporal artery (STA) or a facial artery (FA) pedicle technique (Group I) or an external carotid artery (ECA) pedicle technique. Total harvesting times and lengths of vascular pedicles were measured. RESULTS: Harvesting time for a STA and FA pedicle total facial flap (mean=113min, range = 105-120 min, SD = 6 min) was shorter than that for an ECA pedicle flap (mean = 232 min, range = 225-240 min, SD = 6 min) (P<0.01). Mean pedicle lengths for the STA, the FA, the ECA, the external jugular vein, and the facial vein were 37 +/- 2.1, 35 +/- 1.8, 26 +/- 1.4, 52 +/- 3.0 and 42 +/- 2.6mm, respectively. Mean pedicle lengths for the supraorbital, supratrochlear, infraorbital, mental, and facial nerve were 15 +/- 1.5, 14 +/- 1.4, 24 +/- 1.2, 30 +/- 1.6 and 32 +/- 1.8mm, respectively. CONCLUSION: Compared with previously reported ECA pedicle total facial allograft harvesting techniques, an STA and FA pedicle flap provides a shorter harvesting time and potentially safer dissection method for facial transplantation by avoiding interference with the complicated anatomy of the carotid and submental triangle. Early graft ischaemic damage can be minimised by this harvesting technique, which significantly shortens harvesting time compared with previously described approaches, while maintaining adequate full facial perfusion.

[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.