Acellular Research Articles

Tissue-engineered biological dressing accelerates skin wound healing in mice via formation of provisional connective tissue.

Despite recent advances in bioengineered therapies, wound healing remains a serious clinical problem. In acute full-thickness wounds, it is desirable to replace both the damaged dermis and epidermis in a single procedure. This approach requires appropriate properties of tissue-engineered dressings to support simultaneous regenerative processes in the dermis and epidermis while they are temporally separated in the natural wound healing process. In this study, a collagen-based scaffold inhabited by skin cells was employed. Its ability to stimulate the skin repair of full-thickness excisional splinting wounds in a murine model was evaluated in comparison with that of acellular collagen and commercially available gelatin porous sponge Spongostan®. The study showed that cell-based skin equivalent promoted the immediate filling of the wound bed and provided simultaneous reorganization of the dermal component into highly vascularized granulation-like tissue and rapid epithelialization, thus improving the quality of healing. Inflammation was delayed and less pronounced. In contrast, acellular collagen and especially Spongostan® failed to demonstrate similar results. The porous structure of Spongostan® prevented effective long-term epithelialization and impeded the formation of an adequate connective tissue at the wound bed.

Current evidences on immediate breast reconstruction after mastectomy

Immediate breast reconstruction after mastectomy is widely used: the introduction of skin sparing and nipple sparing mastectomy (NSM) have broaden the viability of different techniques either prosthetic either autologous one. In prosthetic reconstruction, expander is in some case still used, even if one stage reconstruction is preferred. The prosthetic reconstruction is preferred in small breast with minimal/no ptosis and in bilateral cases. The authors explain the different techniques for direct to implant reconstruction: submuscular-subfascial pocket and use of acellular dermal matrix (ADM) (either in subpectoral either in prepectoral plane). The autologous reconstruction is preferred in patients with large breast or with previous radiotherapy. Abdominal flaps are the workhorse because the can provide for large volume flaps and because of the better cosmetic results, even if flaps from areas are available.

Preparation of whole-kidney acellular matrix using peristaltic pump perfusion and identification the composition of matrix

Objective To make a whole-kidney acellular matrix scaffold through the method of peristaltic pump perfusion and to identify whether the kidney acellular matrix reserves extracellular matrix proteins or not. Methods The male Sprague-Dawley (SD) rats, 200~250 g. Intravenous cathers were injected into the renal artery to establish the channels for perfusion, followed by the perfusion of decellularization solution by using peristaltic pumps. After the decellularization, the acellular matrix was observed under microscope after hematoxylin and eosin(HE) staining and fluorescence microscope after DAPI staining. Immunohistochemistry was performed to identify the composition of kidney acellualr matrix. Results The result of HE staining and DAPI staining demonstrate the whole removal of cellular material in kidney acelluar matrix. Immunohistochemistry confirmed the preservation of the natural expression type of extracellular matrix proteins including collagen types I and IV, fibronectin and laminin. Conclusions Peristaltic pump perfusion is a successful method to make the kidney acellular matrix, and this scaffold retains the critical proteins of natural extracellular matrix. Therefore the kidney acellular matrix is an ideal natural scaffold for renal tissue engineering. Key words: Kidney Failure; Peristalsis; Extracellular Matrix

Xenogenic acellular dermal matrix in immediate implant-based breast reconstruction following nipple/skin-sparing mastectomy

Objective To explore the clinical outcomes of xenogenic acellular dermal matrix in immediate implant-based breast reconstruction following nipple/skin sparing mastectomy. Methods From January 2015 to June 2017, patients that underwent immediate implant-based breast reconstruction following nipple/skin-sparing mastectomy were retrospectively studied. Results 43 female patients with breast cancer were enrolled. A retrospective review was performed on patients that were reconstructed with either alloplastic reconstruction (group A, 18 breasts) or xenogenic acellular matrix dermal (group B, 25 groups). Differences in the average age, body mass index, numbers of diabetic patients, numbers of active smoker, and volume of implant between the two groups were not statistically significant (P>0.05). All patients were followed up from 3 to 28 months, with the middle time of 18, 7 months. Complications in both groups of patients were clinically recorded after operation. When comparing clinical outcomes, group A had fewer drain (523.17±62.18) ml vs (639.56±54.34) ml, and fewer days before drain removal (7.83±1.58) d vs (10.2±1.44) d. No significant difference was seen in terms of seroma, hematoma, delayed healing, infection, nipple necrosis, capsular contracture, or tumor recurrence. Conclusions The use of xenogenic acellular matrix dermal in immediate implant-based breast reconstruction following nipple/skin-sparing mastectomy is as safe and effective as alloplastic reconstruction. Key words: Breast cancer; Breast Reconstruction; Breast implantation; Acellular dermis

The effects of recombinant human platelet derived growth factor-BB on biological behaviours of human retinal vascular endothelial cells

Objective This study was to investigate the role of recombinant human platelet derived growth factor-BB(rhPDGF-BB) in the proliferation and migration of human retinal vascular endothelial cells (hRVECs). Methods hRVECs were cultured in DMEM with 10% fetal bovine serum.The rhPDGF-BB at the concentrations of 10, 50 and 200 ng/ml were added into the medium of exponential phase-growth cells for 24 and 48 hours, respectively, and no rhPDGF-BB was added in the normal control group.The proliferation of the cells (absorbancy) was assayed by cell counting kit 8(CCK8) method.Cell scratch test was employed to evaluate the relative migration area of cells (migrated acellular area/initial acellular area). The relative expression of rhPDGF-BB recepter (rhPDGF-BBR) mRNA in the cells was detected by reverse transcription PCR.The relative expression of VEGF mRNA and integrin mRNA in the cells was detected using real-time fluorescence quantitative PCR. Results hRVECs grew well and a expressing band according with rhPDGF-BBR prime was displayed.The absorbancy values of the cells were 1.01±0.05, 1.09±0.04, 1.10±0.02 and 1.13±0.05 in the normal control group and 10, 50, 200 ng/ml rhPDGF-BB groups at 24 hours after culture, and those in the 10, 50 and 200 ng/ml rhPDGF-BB groups were significantly increased in comparison with the normal control group (t=2.504, 3.430, 3.483, all at P<0.05). The relative migrated areas of the cells in the normal control group and 10, 50, 200 ng/ml rhPDGF-BB groups were 0.42±0.10, 0.38±0.09, 0.55±0.06 and 0.61±0.05 at 24 hours after culture, and those at 48 hours were 0.75±0.06, 0.81±0.02, 0.87±0.02 and 0.98±0.02, showing significant differences among the groups (Fgroup=16.283, P=0.000; Ftime=209.129, P=0.000), and the relative migrated areas was depended upon the rhPDGF-BB dose and time.The relative expressions of integrin mRNA were 1.06±0.02, 1.30±0.10, 1.20±0.16 and 1.27±0.08, and those of VEGF mRNA were 0.97±0.05, 1.06±0.16, 1.58±0.18 and 1.66±0.21 in the normal control group and 10, 50 ng/ml, 200 ng/ml rhPDGF-BB groups, respectively, and increased expressions of integrin mRNA and VEGF mRNA were found in the 50 and 200 ng/ml rhPDGF-BB groups compared with the normal control group (integrin mRNA: t=3.900, 4.014, both at P<0.05; VEGF mRNA: t=6.940, 7.210, both at P< 0.05). Conclusions rhPDGF-BB/rhPDGF-BBR signal promotes the proliferation and migration of hRVECs probably by up-regulating the expressions of integrin and VEGF. Key words: Endothelium, vascular/cytology; Neovascularization, pathologic/metabolism; Platelet-derived growth factor; Receptors, platelet-derived growth factor; Recombinant proteins; Humans; Cells, cultured; Integrin; Vascular endothelial growth factor

Potential Use of Amniotic Membrane - Derived Scaffold for Cerebrospinal Fluid Applications.

Scaffolds derived from decellularized tissues provide a natural microenvironment for cell culture. Embryonic cerebrospinal fluid (e-CSF) contains factors which play vital roles in the development of the nervous system. This research was aimed to survey the effect of Wistar rat e-CSF on neural differentiation of bone marrow derived mesenchymal stem cells (BM-MSCs) cultured on the human amniotic membrane (AM). BM-MSCs were collected from femurs and tibias, and were cultured in Dulbecco's Modified Eagle's Medium. The placenta was harvested from healthy women during cesarean section and AM was acellularized using EDTA and physical scrubbing. e- CSF was harvested from rat fetuses at E17. Adequate numbers of BM-MSCs were cultured on acellularized membrane, and were treated with E17 CSF for 7 days. MTT (3-(4, 5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) assay confirmed the survival and proliferation of BM-MSCs cultured on AM derived scaffold. Hematoxylin/eosin staining and scanning electron microscopy showed the morphological and the structural changes of BM-MSCs throughout the culture and treatment with e-CSF. The results of immunocytochemistry showed that microtubule associated protein 2 and beta-III tubulin were expressed in BM-MSCs cultured on acellular amnion scaffold and treated with e-CSF. Our results showed for the first time that the combination of acellular AM as a natural scaffold and e-CSF as a source of neurological factors could effectively improve the BM-MSCs cultivation and differentiation

Prognostic Role of Acellular Mucin Pools in Patients with Rectal Cancer after Pathological Complete Response to Preoperative Chemoradiation: Systematic Review and Meta-Analysis.

The prognostic implication of acellular mucin pools (AMP) in rectal cancer is controversial. There is no Level-I evidence regarding their prognostic impact. This systematic review was performed to determine the impact of AMPon survival in patients with rectal cancer, who demonstrate pathological complete response (PCR) to preoperative chemoradiation (CRT). Asystematic literature review was performed by searching MEDLINE and EMBASE database. For overall survival, the overall random effect model favored mucin negative tumors (HR=2, 95% CI=0.8-4.8) with heterogeneity (I-squared=0, p=0.6). However, the pooled analysis was not significant due to small sample. For disease-free survival, four studies showed HR >1; however, the pooled random effect model indicated little difference in risk (HR=1.06, 95% CI=0.4-2.4) with heterogeneity (I-squared=49.5%, p=0.07). No definite prognostic role of AMPin rectal cancer patients with PCR was found. These results, however, should be interpreted with caution.

The imaging characteristics and nasal endoscopic repair surgery for delayed postoperative cerebrospinal fluid rhinorrhea in patients with pituitary tumor

Objective To investigate the imaging characteristics and nasal endoscopic repair surgery for delayed postoperative cerebrospinal fluid (CSF) rhinorrhea in patients with pituitary tumor. Methods From June 2009 to November 2014 there were 23 cases with delayed CSF rhinorrhea in our hospital, which occurred one year to 5 years after the operation for pituitary tumor. Pituitary hormone assay, head MRI, cisternal CT and nasal endoscopic examination were performed in all patients. After definite diagnosis the patients underwent nasal endoscopic repair surgery of CSF rhinorrhea. During the operation, large leakage orifices were packed with muscle, and then patched with xenogenic acellular dermal matrix, while the small ones were directly patched with xenogenic acellular dermal matrix after tumor resection, and the sphenoid sinus was packed with gelatin sponge and iodoform gauze. Results Patients were hospitalized for 3 to 5 weeks. Among them, 20 patients were successfully recured after one nasal endoscopic repair surgery, 2 underwent the second surgery, and one underwent the third surgery. Patients were followed up for 3 months to 5 years with no CSF rhinorrhea reoccurred. Conclusions Delayed postoperative CSF rhinorrhea in patients with pituitary tumor were likely due to residual tumor growth and postoperative radiotherapy. Pituitary tumor often occur in sella, thus nasal endoscopic resection and repair surgery is feasible in treatment. The surgery is safe and the success rate is high. DOI: 10.3969/j.issn.1672-6731.2017.09.012

Експозиція звитих канальців сім'яників статевонезрілих щурів у кріозахисних середовищах різного композиційного складу

РозN€Ð¾Ð±Ðoа новиN… меN‚одологN–N‡Ð½Ð¸N… Ð?N–дN…одN–в, NÐ?N€NÐ¼Ð¾Ð²Ð°Ð½Ð¸N… на збеN€ÐµÐ¶ÐµÐ½Ð½N Ð?оN‚енN†N–йноN— N„еN€N‚илNŒÐ½Ð¾NN‚N– Ð?N–д N‡Ð°N Ð?ланNƒÐ²Ð°Ð½Ð½N N†Ð¸N‚оN‚оÐoNÐ¸N‡Ð½Ð¾N— N‚еN€Ð°Ð?N–N— Nƒ оNN–б доÐ?NƒÐ±ÐµN€N‚аN‚ного вN–ÐoNƒ, N” аÐoN‚NƒÐ°Ð»NŒÐ½Ð¸Ð¼ наÐ?N€NÐ¼Ðoом медиÐoо-бN–ологN–N‡Ð½Ð¸N… доNÐ»N–дженNŒ. У N€Ð¾Ð±Ð¾N‚N– Ð?N€Ð¾Ð²ÐµÐ´ÐµÐ½Ð¾ Ð?оN€N–внNÐ»NŒÐ½Nƒ оN†N–нÐoNƒ вÐ?ливNƒ еÐoNÐ?озиN†N–N— Nƒ NÐµN€ÐµÐ´Ð¾Ð²Ð¸N‰Ð°N… N€N–зного ÐoомÐ?озиN†N–йного NÐoладNƒ на моN€N„ологN–N‡Ð½N– Ð?аN€Ð°Ð¼ÐµN‚N€Ð¸ N‚а меN‚аболN–N‡Ð½Nƒ аÐoN‚ивнN–NN‚NŒ ÐoлN–N‚ин звиN‚иN… ÐoаналNŒN†N–в NN–м'NÐ½Ð¸ÐoN–в NN‚аN‚евонезN€N–лиN… N‰NƒN€N–в. ÐsN€N–оÐoонNÐµN€Ð²NƒÐ²Ð°Ð½Ð½N N‚Ðoанин NN”N‡Ðoа вимагаN” заNN‚оNNƒÐ²Ð°Ð½Ð½N вN–дÐ?овN–дниN… Ð?N€Ð¾N‚оÐoолN–в, NÐoN– забезÐ?еN‡NƒNŽN‚NŒ виNÐ¾ÐoN– Ð?оÐoазниÐoи жиN‚N‚N”здаN‚ноNN‚N– N‚а N„NƒÐ½ÐoN†N–оналNŒÐ½Ð¾N— аÐoN‚ивноNN‚N– на N‚лN– мN–нN–мN–заN†N–N— Ð?оNˆÐoодженNŒ N‚N€Ð°Ð½NÐ?ланN‚аN†N–йного маN‚еN€N–алNƒ. Ð’NN‚ановлено, N‰Ð¾30-N…вилинна еÐoNÐ?озиN†N–N зN€Ð°Ð·ÐoN–в N‚Ðoанин Nƒ NÐµN€ÐµÐ´Ð¾Ð²Ð¸N‰Ð°N… на оNÐ½Ð¾Ð²N– N€Ð¾Ð·N‡Ð¸Ð½Nƒ ХенÐoNÐ° N‚а50 г/л биN‡Ð°N‡Ð¾Ð³Ð¾ NÐ¸N€Ð¾Ð²Ð°N‚Ðoового алNŒÐ±NƒÐ¼N–нNƒ з додаваннNÐ¼0,6 M димеN‚ил-NNƒÐ»NŒN„оÐoNÐ¸Ð´Nƒ(ДМÐiО) або0,7 M глN–N†ÐµN€Ð¸Ð½Nƒ не виÐoлиÐoала NƒNˆÐoодженNŒ NÐ?еN€Ð¼Ð°N‚огенного еÐ?N–N‚елN–NŽ N‚а зниженнN меN‚аболN–N‡Ð½Ð¾N— аÐoN‚ивноNN‚N– ÐoлN–N‚ин(МТТ-N‚еNN‚ N‚а аÐoN‚ивнN–NN‚NŒ лаÐoN‚аN‚дегN–дN€Ð¾Ð³ÐµÐ½Ð°Ð·Ð¸). ЕÐoNÐ?озиN†N–N вÐ?N€Ð¾Ð´Ð¾Ð²Ð¶45 N‚а60 N…в Nƒ NÐµN€ÐµÐ´Ð¾Ð²Ð¸N‰Ð°N… N–з дода-ваннNÐ¼0,6 Ðœ ДМÐiО, 0,7 Ðœ глN–N†ÐµN€Ð¸Ð½Nƒ, 50 г/л Ð?олN–еN‚иленоÐoNÐ¸Ð´Nƒ-400 N‚а0,1 Ðœ NÐ°N…аN€Ð¾Ð·Ð¸ Ð?N€Ð¸Ð·Ð²Ð¾Ð´Ð¸Ð»Ð° до деNÐoвамаN†N–N—, Ð?оNÐ²Ð¸ безÐoлN–N‚инниN… дN–лNÐ½Ð¾Ðo, зниженнN N‰N–лNŒÐ½Ð¾NN‚N– ÐoлN–N‚ин NÐ?еN€Ð¼Ð°N‚огенного еÐ?N–N‚елN–NŽ N‚а N—N… меN‚аболN–N‡Ð½Ð¾N— аÐoN‚ивноNN‚N–. ОN‚N€Ð¸Ð¼Ð°Ð½N– данN– можNƒN‚NŒ бNƒN‚и виÐoоN€Ð¸NN‚анN– длN обO‘N€NƒÐ½N‚NƒÐ²Ð°Ð½Ð½N N‚а N€Ð¾Ð·N€Ð¾Ð±Ðoи еN„еÐoN‚ивниN… меN‚одиÐo ÐoN€N–оÐoонNÐµN€Ð²NƒÐ²Ð°Ð½Ð½N звиN‚иN… ÐoаналNŒN†N–в NN–м'NÐ½Ð¸ÐoN–в NN‚аN‚евонезN€N–лиN… N‰NƒN€N–в.

Clinical value of human acellular dermal matrix in reconstruction of giant complex abdominal wall defects after open abdomen

Objective To explore the clinical value of human acellular dermal matrix (HADM) in giant complex abdominal wall reconstruction (GCAWR) after open abdomen. Methods The retrospective cross-sectional study was conducted. The clinical data of 6 patients with severe trauma who were admitted to the Nanjing General Hospital of Nanjing Military Command of Nanjing University School of Medicine between January 2013 and January 2014 were collected. After open abdomen, fascia of the abdominal wall was fully freed using the component separation, and abdominal wall defects were reconstructed using HADM in the rectus abdominis anterior sheath and peritoneal layers bridge-type suture. Observation indicators: (1) intra- and post-operative situations: operation time, volume of intraoperative blood loss, removal time of postoperative drainage-tube, postoperative com-plications, duration of hospital stay and hospital expenses; (2) follow-up situations: recurrence of abdominal wall hernia at postoperative year 2. Follow-up using outpatient examination and telephone interview was performed to detect the recurrence of abdominal wall hernia up to April 2016. Measurement data with normal distribution were represented as ±s. Results (1) Intra- and post-operative situations: 6 patients underwent successful surgery. Operation time, volume of intraoperative blood loss and removal time of postoperative drainage-tube were respectively (77±9)minutes, (225±57)mL and (8±3)days. Two patients with postoperative seroma were cured by conservative treatment. One patient with postoperative anastomotic leakage received continuously irrigation and drainage, and leakage was stopped using the biomedical fibrin glue. There was no abdominal bulge of the 6 patients in hospital. Duration of hospital stay and hospital expenses were respectively (10±3)days and (12±7)×104 yuan. (2) Followup situations: 6 patients were followed up for 14-28 months, with a median time of 23 months. Two patients had relaxation and bulge of HADM in peritoneal layer at postoperative 2 years, without bulge of HADM in the rectus abdominis anterior sheath layer. There were no occurrence of abdominal wall hernia, chronic pain, paraesthesia, swelling in the local area and other adverse reaction. Conclusion Using of HADM in the rectus abdominis anterior sheath and peritoneal layers bridgetype suture is safe and feasible for GCAWR, with good short-term outcomes. Key words: Complex abdominal wall defect; Open abdomen; Human acellular dermal matrix

Coadministering Recommended Vaccines at 11-to-12-Year Visit Could Improve HPV Vaccination Rates

Although the Centers for Disease Control and Prevention recommends administration of tetanus–diphtheria–acellular pertussis (Tdap), human

A New Live Attenuated Pertussis Vaccine Protects Against Disease and Colonization

Pertussis is resurgent despite global vaccination rates of >85%. One possible reason is the persistent reservoir of asymptomatic carriers of Bordetella pertussis . The effect of vaccination on asymptomatic nasal colonization has been difficult to assess in animal models, but a recently developed baboon model indicates that neither a whole-cell or acellular vaccine was completely protective. In contrast, prior …

A natural pancreatic 3D bioscaffold platform for in vitro study on exocrine pancreas

Objective To evaluate the biochemical function of rat nature three-dimensional acellular pancreatic bioscaffold (3D-APB) in promoting cell proliferation and differentiation in vitro. Methods The fresh pancreas from 10 rats were perfused to prepare 3D-APB. The biocompatibility of 3D-APB was eva-luated. The experiment was divided into 4 groups based on 4 kinds of three-dimensional media for AR42J culture, including blank control group, ECM group, PLGA group and 3D-APB group. We compared the proliferation and differentiation of AR42J pancreatic acinar cell at 3 days, 5 days, 7 days and 10 days after seeding among 4 groups. Results The 3D-APB could represent a biocompatible scaffold capable of integrating within host tissue. The proliferation rate of AR42J cells by MTT in 3D-APB was higher, while the apoptosis rate by flow cytometry was lower than those in other 3 media, which were all significantly different (P<0.05), respectively. The protein expression of PDX-1 and PTF-1 by western blot in 3D-APB group was greatly higher than those in other 3 groups (both P<0.05). The mRNA expression of PDX-1 and PTF-1 through qRT-PCR was significantly higher than those in other 3 groups (both P<0.05). Conclusion Compared with the commonly used chemical and natural scaffold at present, 3D-APB could promote cell proliferation and differentiation, which was more appropriate for regenerative medicine. Key words: Acellular scaffold; Acellular matrix; Pancreas; Acinar cell; Proliferation; Differentiation

Study progress of immune response induced by natural infection and pertussis vaccines

Previous researches mainly focus on the role of B cell-mediated humoral immunity to Bordetella pertussis infection, while, there is a growing evidence that CD4+ T cell-mediated cellular immunity is necessary for clearance of B. pertussis infection.Many subsets of CD4+ T cells have been described, T helper lymphocyte(Th)1, Th2 and Th17, which differ in their cytokine production profiles.Several experiments indicated that Th1 and Th17 cells were necessary for completely B. pertussis clearance.While, both animal and human studies have been showed that natural infection and whole cell pertussis (wP) vaccines promote Th1/Th17 responses, whereas acellular pertussis (aP) vaccines induce Th2/Th17 responses.The different profiles of immune response induced by wP and aP vaccines, in part, explain the resurgence of pertussis. Key words: Pertussis; Whole cell pertussis vaccines; Acellular pertussis vaccines; Cellular immunity

The application of acellular bovine pericardium patch in secondary hydroxyapatite prosthesis implantation

Objective To evaluate the clinical efficacy and safety of application of acellular bovine pericardium patch in secondary hydroxyapatite prosthesis implantation. Methods The hydroxyapatite prosthesis were implanted wrapped with acellular bovine pericardium patch in 46 eyes of 46 cases. All patients were followed up for 6-24 months. The efficacy of surgery was evaluated and analyzed. Results In 46 cases, 43 cases (93.48%) were primary healing. Poor healing of bulbar conjunctival and Tenon capsule occurred in 3 cases. They were healed after conservative treatment. At the end of follow-up, no prosthesis exposure, immigration or inflammation occurred. Conclusion Acellular bovine pericardium patch is the best substitute of autologous or allogeneic tissue used in implantation to wrap the prosthesis. Key words: Prosthesis, hydroxyapatite; Bovine pericardium patch, acellular; Enucleation, eyeball

Wound surface thinning combined with acellular dermal matrix in the treatment of adult deep II-degree burn

Wound surface thinning combined with acellular dermal matrix in the treatment of adult deep II-degree burn

Clinical research progress on tissue defect repairing with acellular dermal matrices

Acellular dermal matrix(ADM) is a special biological material that contains only collagen, elastin and other extracellular matrix. ADMs are made by special methods of separating skin epidermis and dermis, and removing Langerhans cells, vascular endothelial cells, fibroblasts cells and major histocompatibility complex (MHC) within the dermis. ADM causes no graft rejection, and provides a good scaffold for tissue reconstruction, angiogenesis and implantation of host cells. The preparation process of ADM includes the separation of epidermis and dermis, decellularization, perforation and freeze-drying. According to the classification method, ADMs can be classified into allogeneic and xenogeneic ADM, patch and injection type ADM, as well as cross-linked and non-crosslinked ADM, which can meet various clinical requirements. ADM is widely used in surgical field, such as treatment of deep burn wounds, breast reconstruction after mastectomy, oral mucosa repair, abdominal wall hernia repair, and treatment of vocal cord paralysis. Due to the characteristics ADM, its application prospect is considerable. The research progress of ADM in recent years was summarized. Key words: Acellular dermal matrix; Preparation; Clinical application

Advances in the construction of tissue-engineered cornea in vitro

Corneal transplantation is the most effective treatment for corneal blindness at present, but the shortage of cornea donation and graft rejection are the serious obstacles for its broad application.Construction of tissue-engineered corneal substitutes with good biocompatibility and normal biological function is emerging as a potential approach to overcome the shortages of donor corneas, and which will be a potential source of corneal grafts for corneal transplantation.With the development in the technology of biomaterials, cell culture and tissue engineering, the field of corneal tissue engineering has made great strides in scaffolds, seed cells and three-dimensional reconstruction recently, and also start to be used in clinical practice.The tissue-engineered cornea with good mechanical property, light transmittance and biocompatibility may serve as an ideal candidate in the treatment of corneal diseases.Amniotic membrane, acellular porcine corneal matrix, collagen, silk fibroin, and chitosan are frequently-used scaffold for cornea tissue engineering.Currently, immortalized and primary cultured corneal cells, embryonic stem cells, and adult stem cells have been reported to be used as seed cells in the construction of tissue-engineered cornea.This chapter reviewed the advances made in tissue-engineered cornea, including scaffolds, seed cells, and three-dimensional reconstruction. Key words: Tissue engineering; Cornea; Seed cell; Scaffold; Three-dimensional reconstruction

The effects of inner vertical outer spiral complex scaffold in repairing long segment of urethral defect

Objective To explore the possibility of the inner vertical outer spiral complex tubular urethra scaffold vascularization in repairing long segment of urethral defect. Methods From August 2014 to October 2015, 27 clean male New Zealand white rabbits were divided into 3 groups, S1 group was transfected recombinant vascular endothelial growth factor(VEGF) gene lentiviral vector group. S2 group was vascular pedicle transfer tube group. C group was simple stent group. A 3.0 cm inner vertical outer spiral complex scaffold was constructed by using the small intestine acellular matrix (SIS) and polylactic acid copolymer (PLGA) modified by type Ⅰ collagen surface, and adipose-derived mesenchymal stem cells (ADSC) and smooth muscle cells after transformation from New Zealand white rabbits. In S1 group, the seed cells were transfected by recombinant vascular endothelial growth factor (VEGF) gene lentivirus, which express VEGF protein.The complex scaffold was used to repair 3.0 cm rabbit urethral defect In S2 group, the un-transfected cells were seeded into the scaffold and embedded in the skin near the groin artery 3 weeks for repairing urethral defect with vascular pedicle transfer tube. In group C, the unseeded scaffold was used to repair the urethral defect alone.Postoperative observation and urethrography were followed 4, 8 and 24 weeks after implantation. The HE staining, fluorescence tracing, immunohistochemical and scanning electron microscopy were evaluated at the same phase. Results In S1 group, there were one urinary fistula and one urethral stricture-related death, respectively. The urethra was smooth and patent, histological examination showed active hyperplasia of urethral capillary. In S2 group, there were one urinary fistula and two urethral stricture-related deaths, respectively. The urethral was rough, local thinning or dilated. Fat accumulation and mucosal contraction were found in the urethral submucosal, respctively. In C group, there were one urinary fistula, three hypospadias, and three urethral stricture-related deaths. The thickness of the urethra was uneven and stricture bending. The urethral mucosa was poorly repaired and the scar was narrow. HE and CD31 staining showed that S1 and S2 groups were active in the proliferation of urethral capillaries, and the angiogenesis was abundant. VEGF staining showed that the cytoplasm of endothelial cell layer, smooth muscle layer of vascular wall and the urothelial epithelial cell layer were fully expressed at 24 weeks, especially in epithelial cell layer. CKpan staining showed that the epithelium of S1 and S2 group developed to stratified epithelium, and the morphology of urethra was similar to normal urethra at 24 weeks. The urethral epithelial in C group of grew poor as single-level, irregular arrangement, 24 weeks is still a lack of effective stratified epithelium. HE and α-SMA staining showed that the smooth muscle and actin gradually increased in group S1 and S2, α-SMA staining in group C was scarce and increased at 24 weeks. PLGA was encapsulated by the surrounding tissue and the structure of electrospinning was clear after 4 weeks, absorbed and degraded after 8 weeks and absorbed after 24 weeks. Conclusions The inner vertical outer spiral complex tubular urethra scaffold maybe a reasonable method in repairing long segment urethral defects, and the methods of tubular urethra scaffold vascularization by transfected VEGF gene recombinant lentiviral vector and vascular flap deserve more research. Key words: Tissue engineering; Scaffold; Urethra defect; Vascularization

Establishment of rabbit radius fracture model and the role of stromal vascular fraction-acellular bone extracellular matrix-chitosan scaffold in promoting the healing of rabbits

Objective To prepare stable structure and good bone induction and biological compatibility of stromal vascular fraction (SVF)-acellular bone extracellular matrix(ABECM)-chitosan composite scaffold study SVF-ABECM-chitosan scaffolds to promote the healing of rabbit radius fracture. Methods Using Triton X-100 and sodium dodecyl sulfate (SDS) acellular method of porcine femur were decellularized, using a solution blending, freeze drying method preparing ABECM-chitosan composite scaffolds. The qualitative analysis of SVF-ABECM-chitosan scaffolds, observe SVF-ABECM-chitosan composite porous scaffold morphology, porosity, mechanical properties and cell scaffold composite culture compatibility.12 adult healthy New Zealand white rabbits were selected, and the fracture model was caused by the fracture gap of about 0.3 cm, which was exposed to the radial shaft of the radial side of the forearm of the rabbit. The SVF-ABECM-chitosan composite scaffold was prepared in the right radius fracture space of each animal, and the left side was the blank control group. The fracture healing was compared between the two sides of the radius fracture model of rabbits by X-ray, biomechanical test and tissue morphology. Results ABECM materials were stained with he and hoechest 33258 fluorescence staining showed no residual cells, immunohistochemical staining of alizarin red staining and type I collagen and bone morphogenetic occurred protein-2 antibody staining positive. Scanning election microscopy (SEM) showed that the scaffolds have a porous structure, the aperture 50-200 μm, porosity of (53.50±4.23)%, dry mechanical test support longitudinal compression modulus is (33.23±14.45) mPa, support wet state of compression modulus of (2.27±1.13) mPa. Cell scaffold composite culture has good compatibility. After 4 weeks and 12 weeks in the experimental group by X-ray films reflect the bone healing was stronger than that of the control group. After 12 weeks, the biomechanical test group in the maximum load, anti bending strength of HA load/displacement parameters and control group comparison differences were statistically significant, and elastic modulus difference were statistically significant (t=7.418, 5.131 and 2.838, P=0.004, 0.009 and 0.027), and elastic modulus difference between the two groups no statistical significance (t=1.455, P=0.064), at 12 weeks after operation, the histomorphometric results showed. In experimental group, the bone and shaping was significantly better than the control group. Conclusion Preparation of ABECM-CS composite porous scaffolds to cells completely, retained the removal of cells from the bone matrix main component, have the appropriate aperture and porosity, cell compatibility is good. SVF-ABECM-chitosan composite scaffold can effectively promote the healing of rabbit radius fracture. Key words: Stromal vascular fraction; Acellular bone matrix; Chitosan; Radius fracture; Rabbit