Objective To research the effect of porcine acellular dermal matrix in the reconstruction of abdominal wall defects in rabbits, and to investigate the appl ication feasibil ity of xeno-transplantation of acellular dermal matrix. Methods The porcine acellular dermal matrix was prepared from a health white pig. Twenty-six Japanese white rabbits (weighing 2.2-2.3 kg, female or male) were randomly assigned to 2 groups: the control group (n=6) and the experimental group (n=20). In the control group, the full-thickness abdominal wall defect of 5.0 cm × 0.5 cm was made, and the defect wassutured directly; in the experimental group, the full-thickness abdominal wall defect of 5.0 cm × 2.5 cm was made, and the defect was repaired with porcine acellular dermal matrix patch at the same size as the defect. At 5 weeks after surgery, the incidence of hernia and the intra-abdominal adhesions were observed and the wound breaking strength was compared between the patchfascia interface and the fascia-fascia interface. The graft vascularization was evaluated through histological analysis at 6 months after surgery in the experimental group. Results No hernia occurred in all rabbits of 2 groups. At 5 weeks after surgery, heal ing was observed between patch and the muscularfascia; the vascularization was seen in the porcine acellular dermal matrix patch. There was no significant difference in the adhesion grade (Z= —0.798, P=0.425) between the experimental group (grade 2 in 1 rabbit, grade 1 in 5, and grade 0 in 12) and the control group (grade 1 in 1 and grade 0 in 5). No significant difference was found (t= —0.410, P=0.683) in the breaking strength between the patch-fascia interface in the experimental group [(13.0 ± 5.5) N] and the fascia-fascia interface in control group [(13.6 ± 4.0) N]. In the experimental group, the small vessels and the infiltration of inflammatory cells were observed in the porcine acellular dermal matrix patch after 5 weeks through histological observations. The junctions of the patch-fascia interface healed with fibrous connective tissue. At 6 months after surgery, the inflammation was subsided and the collagen fiber of the patch was reconstructed. Conclusion The porcine acellular dermal matrix patchhas good results in repairing full-thickness abdominal wall defect. The patch-fascia interface has siml iar breaking strength to the fascia-fascia interface. The collagen fibers of the patch are reconstructed.
Objective To compare the effect of the composite skin graft consisting of spl it-thickness skin grafts (STSGs) and porcine acellular dermal matrix (PADM) with STSGs only, and to histologically observe the turnover of the PADM in rats. Methods Twenty female Sprague-Dawley rats, weighing 200-225 g, were included. The size of 4.0 cm × 2.5 cm PADM was implanted into hypoderm of the left side of Sprague-Dawley rats’ back. After 10-14 days, the size of 4.0 cm × 2.5 cm full-thickness skin defects were made on the left to expose the PADM under the skin and the same size of full-thickness skin defects were made on the right of the rats’ back. The excised full-thickness skin was made to STSGs about 0.2 mm by drum dermatome. The defects were grafted with composite skin (STSGs on the PADM, experimental group) and STSGs only (control group). The survival rate, the constraction degree of grafts, and the histological change in grafts area were observed at 2, 4, 8, and 20 weeks after operation. Results At 2 weeks after STSGs (0.2 mm) placed on vascularized PADM, STSGs and PADM adhered together and the composite skin had a good survival. The control group also had a good survival. Histological observations showed that STSGs and PADM grew together, neutrophil ic granulocytes and lymphocytes infiltrated in the PADM and some macrophages around the PADM. Fibrous connective tissues were filled under the STSGs in control group. At 4-8 weeks after transplantation, the composite skin had a good survival and the composite skin was thick, soft, and elastic. STSGs survived almost totally in control group, but the grafts were thin. Histological observations showed that inflammatory reactions of PADM faded gradually in experimental group; scar tissues formed under the STSGs in control group. At 20 weeks after transplantation, composite skin was flat, thick, and elastic in experimental group, but the STSGs were thinner and less elastic in control group. Histological observations showed that histological structures of the PADM were similar to the dermal matrix of rats, and the results showed that the collagen matrix of PADM was gradually replaced by the rats’ collagen matrix. Scar tissues were filled under the STSGs in control group. Wound heal ing rates of experimental group were lower than those of control group at 4 and 8 weeks (P﹤0.05); wound contraction rates of experimental group had lower tendency than those of control group, but showing no significant differences (P gt; 0.05). Conclusion Coverage wound with composite skin which composed of STSGs and PADM could improve wound heal ing qual ity; the composite skin is thicker and better elastic than STSGs only. The collagen matrix of PADM is gradually replaced by rats’ collagen matrix.
Objective To summarize the cl inical effect of allogenic acellular dermal matrix in repair of abdominal wall hernia and defect. Methods The cl inical data were analyzed retrospectively from 31 patients with abdominal wall hernia and defect repaired by allogenic acellular dermal matrix between March 2007 and November 2009. There were 19 males and 12females with an age range of 10-70 years (median, 42 years), including 6 abdominal wall defects caused by abdominal wall tumor resection, 4 patchs infection after abdominal wall hernia repair using prosthetic mesh, 2 incisional hernia, 1 parastomal hernia, 1 recurrent parastomal hernia receiving mesh repair, 1 mesh infection caused by parastomal hernia repair using prosthetic patch, 3 mesh infection caused by tension free inguina after hernia repair, and 13 inguinal hernia. There were 12 patients with contaminated or infectious wound. The disease duration was from 1 to 34 months (6 months on average). The defect size of abdominal wall ranged from 6 cm × 4 cm to 19 cm × 10 cm. Abdominal wall hernia or defect underwent repair using allogenic acelluar demall matrix. Results Of the 31 patients, 29 patients recovered with primary wound heal ing. Chronic sinus tract occurred in 1 patient and the wound was cured by change dressing. Wound dehiscence and patch exposure occurred in 1 patient, and second heal ing was achieved after change dressing. All the 31 patients were followed up 6-36 months, no abdominal wall hernia or hernia recurrence occurred in other patients except 1 patient who had abdominal bulge. And no foreign body sensation or chronic pain in wound area occurred. Conclusion It is feasible and safe to use allergenic acellular dermal matrix patch for repair of abdominal wall hernia or soft tissue defect, especially in contaminated or infectious wound.
Objective To investigate the effect of ultra-filtration on reducing the matrix effects of the immersionof recombination human acellular dermal matrix (rhADM) on detecting residual bovine serum albumin (BSA) by ELISA.Methods Preparation of rhADM immersion: rhADM were rinsed, and then rhADM immersion were prepared. Physiologicalsal ine was used as immersion medium. Presaturation and ultra-filtration: marked the ultra-filtration tubes as PR1 (presaturation protocol 1), PR2 (presaturation protocol 2) and rhADM, respectively, added 2 mL of 1 mg/mL and 10 μg/mL BSA solution into PR1 and PR2 respectively, and added 2 mL of rhADM immersion into rhADM tubes (rhADM1 and rhADM2). The tubes were then centrifuged at 1 500 × g for 20 minutes. The above steps were repeated for 3 times. Take the inner-tube of ultrafiltration into unused centrifuge tube. Added 4 mL of 10 μg/mL BSA solution in PR1 and PR2 tubes, 4 mL of rhADM immersion in rhADM tubes, centrifuged at 1 500 × g for 20 minutes, and then the filtration was colleted. Detecting BSA concentration: the BSA concentrations of all samples were detected by using the quantitative measure of residual BSA ELISA kit. The recoveries of 10 μg/ mL BSA solution treated by presaturation protocol 1 and 2 were calculated (untreated 10 μg/mL BSA solution was as the basic sample, marked R10 and R20 respectively). The correlation coefficient between the logarithm of the filtrate dilution and the absorbance (A) value was calculated and compared with that of water exact without ultra-filtration. Results The BSA concentration of PR1 and R10 was (23.80 ± 1.58) μg/ mL and (9.04 ± 0.24) μg/mL, respectively. The BSA concentration of PR2 and R20 was (8.64 ± 0.24) μg/mL and (8.12 ± 1.01) μg/ mL, respectively. The average recovery of 10 μg/mL BSA was 263.4% ± 16.9% and 106.5% ± 3.0% when the ultra-filtration tubes were presaturaed by PR1 and PR2 (P lt; 0.01), respectively. The BSA recovery of PR2 met the detecting demand. The correlations between A value and sample dilution were increased, the correlationcoefficient was raised from — 0.727 to — 0.960 after rhADM immersion were treated by ultra-filtration. Conclusion Theresults show that the matrix effects can be reduced effectively by ultra-filtration, indicating that an acceptable recovery of BSA can be acquired when ultra-filtration tube is presaturated by sample water extract.
OBJECTIVE: To investigate the effect of heterogeneous (swine) acellular dermal matrix (s-ADM) and autologous overthin split-thickness skin (auto-OTS) composite grafting in repair of deep burns at articular sites. METHODS: From May 1999 to April 2000, 19 articular sites in 16 patients, including 14 males and 2 females, were treated. In all the 19 sites of deep burn, the total burn area varied from 2% to 48% and the full-thickness burn area varied from 1% to 35%. After the primary escharectomy (1 to 5 days later) and complete hemostasis, the s-ADM was utilized to cover the exposed articular sites and the auto-OTS was transferred on the surface of sutured s-ADM. The size of s-ADM applied to each patient varied from 25 cm2 to 150 cm2. Regular skin grafting was adopted elsewhere other than the articular site. The survival rate of all skin grafting was evaluated and pathological examination was performed. RESULTS: The survival rate of the composite skin was (90.80 +/- 18.34)%, which was obvious higher than the survival rate of contiguous granulosum skin grafting (P lt; 0.05) and almost the same with that of snip skin grafting(P gt; 0.05). The survived composite skin appeared as smooth and soft as normal skin, and the function of articular site almost recovered with neglectable hypertrophic scar. The pathological examination revealed that the normal cell grew into s-ADM with regularly arranged collagen fiber and neovascularization in the matrix. CONCLUSION: The combination of s-ADM and auto-OTS graft is cheap and effective method to cover wound and minimize hypertrophic scar.
ObjectiveTo investigate the histological changes and vascularization of the porcine acellular dermal matrix (P-ADM) processed with matrix metalloproteinase 7 (MMP-7) (P-ADM-pm) after implanted into rats. MethodsSixty-two pieces of porcine reticular layer dermis which were from the pig abdominal skin and obtained by using a mechanical method, were randomly divided into group A (n=31) and group B (n=31). The porcine reticular layer dermis in 2 groups were treated with decellularization (P-ADM), then the P-ADM in group B were treated with processing by MMP-7 (P-ADM-pm). Thirty adult male Wistar rats were selected. P-ADM (group A) and P-ADM-pm (group B) were subcutaneously transplanted into the left and right fascia lacuna, respectively. The implants were harvested from 6 rats at 3, 7, 14, 21, and 28 days after implantation, respectively. Gross, histochemical, and immunohistochemical observations, and scanning electron microscopy (SEM) examination were performed to observe host cells, microvessels infiltration and histological changes in the implants. ResultsNo rat died in the experiment, incision healed well and no obvious inflammatory reaction was seen in all rats. Gross observation suggested that the implants of 2 groups were encapsulated by a thin layer of connective tissue at 7 days after implantation. With the time of implantation, the microvessels increased and coarsened, and the changes of group B were more obvious than those of group A. At 21 days, the microvessels of 2 groups decreased, and the implants of group B showed complete vascularization. The histochemical and immunohistochemical observations showed that group A had more severe inflammatory response than group B. Fibroblasts and microvessels in group B appeared in the superficial zone of implant at 3 and 7 days after implantation and they could be observed in the center zone of implant at 14 and 21 days. However, fibroblasts and microvessels in group A appeared in the superficial zone of implant at 3 and 14 days and they could not be observed in the center zone of implant at 28 days. Fibroblasts and microvessels of group B were significantly more than those of group A (P < 0.05). SEM examination showed that more fibroblasts and new collagen fibrils were observed in group B at 14 days. ConclusionThe host response to P-ADM-pm is similar to normal wound healing, and P-ADM-pm as implantable scaffold material plays a good template conduction role.
Objective To evaluate the application effect of acellular dermal matrix (ADM) in immediate breast reconstruction after mammary mastectomy with prosthetic implants. Methods The clinical data of 68 patients with breast cancer undergoing immediate breast reconstruction with prosthetic implantation in our hospital were retrospectively analyzed and divided into ADM group (n=43) and non-ADM group (n=25), according to the use of ADM in the posterior space of pectoralis major muscle while prosthesis implantation or not. The size of breast prosthesis, operative time, intraoperative blood loss, drainage duration, total drainage, total hospital stay, postoperative complications, postoperative cosmetic effect and quality of life of patients were compared between the two groups. Results Patients in the ADM group showed no statistically significant difference regarding operative time, drainage duration, total drainage, hospital stay, postoperative complications and intraoperative removed gland volume with the non-ADM group (P>0.05). The average intraoperative blood loss in the ADM group was less than that of the non-ADM group, the average volume of prosthesis in the ADM group was bigger than that of the non-ADM group, the volume difference between prosthesis and removed gland in the ADM group was smaller than that of the non-ADM group, which was considered statistically significant difference (P<0.05). The subjective satisfaction and objective measurement scores of patients in the ADM group were significantly better than those of the non-ADM group, especially in the symmetry of breast, surgical scar and distance of lateral displacement of nipple (P<0.05). The postoperative quality of life in the ADM group was significantly better than that of the non-ADM group in terms of body image, sexual function and sexual interest (P<0.01). Conclusions It is safe and feasible to use ADM-assisted the immediate breast reconstruction after nipple-sparing mammary mastectomy with prosthetic implantation. As an extension of the pectoralis major muscle, ADM can enlarge the posterior space for the prosthesis implantation, making the choice of the prosthesis much more easier. The combined application of ADM can obtain a better cosmetic effect, meanwhile improving the postoperative quality of life and satisfaction of patients.
Objective To overview the theoretical basis and research status of prepectoral implant-based breast reconstruction. Methods The domestic and foreign researches on the application of prepectoral implant-based breast reconstruction in breast reconstruction were retrospectively analyzed. The theoretical basis, clinical advantages, and limitations of this technique were summarized and the future development trend in this field was discussed. Results The recent advances in breast cancer oncology, the development of materials and the concept of oncology reconstruction have provided a theoretical basis for prepectoral implant-based breast reconstruction. The selection of patients and the experience of surgeons are crucial for postoperative outcomes. Ideal thickness and blood flow of flaps are the most important considerations for the selection of prepectoral implant-based breast reconstruction. However, its long-term reconstruction outcomes and clinical benefits and risks in Asian populations still need to be confirmed by more studies. Conclusion Prepectoral implant-based breast reconstruction has a broad application prospect in breast reconstruction following mastectomy. However, the evidence is limited at present. Randomized study with long-term follow-up is urgently in need to provide sufficient evidence to evaluate the safety and reliability of prepectoral implant-based breast reconstruction.
Objective To investigate the physicochemical properties, osteogenic properties, and osteogenic ability in rabbit model of femoral condylar defect of acellular dermal matrix (ADM)/dicalcium phosphate (DCP) composite scaffold. Methods ADM/DCP composite scaffolds were prepared by microfibril technique, and the acellular effect of ADM/DCP composite scaffolds was detected by DNA residue, fat content, and α-1, 3-galactosyle (α-Gal) epitopes; the microstructure of scaffolds was characterized by field emission scanning electron microscopy and mercury porosimetry; X-ray diffraction was used to analyze the change of crystal form of scaffold; the solubility of scaffolds was used to detect the pH value and calcium ion content of the solution; the mineralization experiment in vitro was used to observe the surface mineralization. Twelve healthy male New Zealand white rabbits were selected to prepare the femoral condylar defect models, and the left and right defects were implanted with ADM/DCP composite scaffold (experimental group) and skeletal gold® artificial bone repair material (control group), respectively. Gross observation was performed at 6 and 12 weeks after operation; Micro-CT was used to detect and quantitatively analyze the related indicators [bone volume (BV), bone volume/tissue volume (BV/TV), bone surface/bone volume (BS/BV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp), bone mineral density (BMD)], and HE staining and Masson staining were performed to observe the repair of bone defects and the maturation of bone matrix. Results Gross observation showed that the ADM/DCP composite scaffold was a white spongy solid. Compared with ADM, ADM/DCP composite scaffolds showed a significant decrease in DNA residue, fat content, and α-Gal antigen content (P<0.05). Field emission scanning electron microscopy showed that the ADM/DCP composite scaffold had a porous structure, and DCP particles were attached to the porcine dermal fibers. The porosity of the ADM/DCP composite scaffold was 76.32%±1.63% measured by mercury porosimetry. X-ray diffraction analysis showed that the crystalline phase of DCP in the ADM/DCP composite scaffolds remained intact. Mineralization results in vitro showed that the hydroxyapatite layer of ADM/DCP composite scaffolds was basically mature. The repair experiment of rabbit femoral condyle defect showed that the incision healed completely after operation without callus or osteophyte. Micro-CT showed that bone healing was complete and a large amount of new bone tissue was generated in the defect site of the two groups, and there was no difference in density between the defect site and the surrounding bone tissue, and the osteogenic properties of the two groups were equivalent. There was no significant difference in BV, BV/TV, BS/BV, Tb.Th, Tb.N, and BMD between the two groups (P>0.05), except that the Tb.Sp in the experimental group was significantly higher than that in the control group (P<0.05). At 6 and 12 weeks after operation, HE staining and Masson staining showed that the new bone and autogenous bone fused well in both groups, and the bone tissue tended to be mature. Conclusion The ADM/DCP composite scaffold has good biocompatibility and osteogenic ability similar to the artificial bone material in repairing rabbit femoral condylar defects. It is a new scaffold material with potential in the field of bone repair.