A comparison of three methods of decellularization of pig corneas to reduce immunogenicity

·AIM: To investigate whether decellularization using different techniques can reduce immunogenicity of the cornea, and to explore the decellularized cornea as a scaffold for cultured corneal endothelial cells(CECs).Transplantation of decellularized porcine corneas increases graft transparency and survival for longer periods compared with fresh grafts.·METHODS: Six-month-old wild-type pig corneas were cut into 100-200 μm thickness, and then decellularized by three different methods: 1) 0.1% sodium dodecyl sulfate(SDS); 2) hypoxic nitrogen(N2); and 3) hypertonic NaCl. Thickness and transparency were assessed visually. Fresh and decellularized corneas were stained with hematoxylin/eosin(H&E), and for the presence of galactose-α1,3-galactose(Gal) and N-glycolylneuraminic acid(NeuGc, a nonGal antigen). Also, a human IgM/IgG binding assay was performed. Cultured porcine CECs were seeded on the surface of the decellularized cornea and examined after H&E staining.· RESULTS: All three methods of decellularization reduced the number of keratocytes in the stromal tissue by 】80% while the collagen structure remained preserved. No remaining nuclei stained positive for Gal or NeuGc, and expression of these oligosaccharides on collagen was also greatly decreased compared to expression on fresh corneas. Human IgM/IgG binding to decellularized corneal tissue was considerably reduced compared to fresh corneal tissue. The cultured CECs formed a confluent monolayer on the surface of decellularized tissue.· CONCLUSION: Though incomplete, the significant reduction in the cellular component of the decellularized cornea should be associated with a significantly reduced in vivo immune response compared to fresh corneas.

Application of decellularization-recellularization technique in plastic and reconstructive surgery

In the field of plastic and reconstructive surgery,the loss of organs or tissues caused by diseases or injuries has resulted in challenges,such as donor shortage and immunosuppression.In recent years,with the development of regenerative medicine,the decellularization-recellularization strategy seems to be a promising and attractive method to resolve these difficulties.The decellularized extracellular matrix contains no cells and genetic materials,while retaining the complex ultrastructure,and it can be used as a scaffold for cell seeding and subsequent transplantation,thereby promoting the regeneration of diseased or damaged tissues and organs.This review provided an overview of decellularization-recellularization technique,and mainly concentrated on the application of decellularization-recellularization technique in the field of plastic and reconstructive surgery,including the remodeling of skin,nose,ears,face,and limbs.Finally,we proposed the challenges in and the direction of future development of decellularization-recellularization technique in plastic surgery.

Biomaterial engineering strategies for modeling the Bruch's membrane in age-related macular degeneration

Age-related macular degeneration,a multifactorial inflammatory degenerative retinal disease,ranks as the leading cause of blindness in the elderly.Strikingly,there is a scarcity of curative therapies,especially for the atrophic advanced form of age-related macular degeneration,likely due to the lack of models able to fully recapitulate the native structure of the outer blood retinal barrier,the prime to rget tissue of age-related macular degeneration.Standard in vitro systems rely on 2D monocultures unable to adequately reproduce the structure and function of the outer blood retinal barrier,integrated by the dynamic interaction of the retinal pigment epithelium,the Bruch's membrane,and the underlying choriocapillaris.The Bruch's membrane provides structu ral and mechanical support and regulates the molecular trafficking in the outer blood retinal barrier,and therefo re adequate Bruch's membrane-mimics are key for the development of physiologically relevant models of the outer blood retinal barrie r.In the last years,advances in the field of biomaterial engineering have provided novel approaches to mimic the Bruch's membrane from a variety of materials.This review provides a discussion of the integrated properties and function of outer blood retinal barrier components in healt hy and age-related macular degeneration status to understand the requirements to adequately fabricate Bruch's membrane biomimetic systems.Then,we discuss novel materials and techniques to fabricate Bruch's membrane-like scaffolds for age-related macular degeneration in vitro modeling,discussing their advantages and challenges with a special focus on the potential of Bruch's membrane-like mimics based on decellularized tissue.

High quality repair of osteochondral defects in rats using the extracellular matrix of antler stem cells

BACKGROUND Cartilage defects are some of the most common causes of arthritis.Cartilage lesions caused by inflammation,trauma or degenerative disease normally result in osteochondral defects.Previous studies have shown that decellularized extracellular matrix(ECM)derived from autologous,allogenic,or xenogeneic mesenchymal stromal cells(MSCs)can effectively restore osteochondral integrity.AIM To determine whether the decellularized ECM of antler reserve mesenchymal cells(RMCs),a xenogeneic material from antler stem cells,is superior to the currently available treatments for osteochondral defects.METHODS We isolated the RMCs from a 60-d-old sika deer antler and cultured them in vitro to 70%confluence;50 mg/mL L-ascorbic acid was then added to the medium to stimulate ECM deposition.Decellularized sheets of adipocyte-derived MSCs(aMSCs)and antlerogenic periosteal cells(another type of antler stem cells)were used as the controls.Three weeks after ascorbic acid stimulation,the ECM sheets were harvested and applied to the osteochondral defects in rat knee joints.RESULTS The defects were successfully repaired by applying the ECM-sheets.The highest quality of repair was achieved in the RMC-ECM group both in vitro(including cell attachment and proliferation),and in vivo(including the simultaneous regeneration of well-vascularized subchondral bone and avascular articular hyaline cartilage integrated with surrounding native tissues).Notably,the antler-stem-cell-derived ECM(xenogeneic)performed better than the aMSC-ECM(allogenic),while the ECM of the active antler stem cells was superior to that of the quiescent antler stem cells.CONCLUSION Decellularized xenogeneic ECM derived from the antler stem cell,particularly the active form(RMC-ECM),can achieve high quality repair/reconstruction of osteochondral defects,suggesting that selection of decellularized ECM for such repair should be focused more on bioactivity rather than kinship.

Improved the biocompatibility of cancellous bone with compound physicochemical decellularization process

Due to the unique microstructures and components of extracellular matrix(ECM),decellularized scaffolds had been used widely in clinical.The reaction of the host toward decellularized scaffolds depends on their biocompatibility,which should be satisfied before applied in clinical.The aim of this study is to develop a decellularized xenograft material with good biocompatibility for further bone repair,in an effective and gentle method.The existing chemical and physical decellularization techniques including ethylene diamine tetraacetic acid(EDTA),sodium dodecyl sulfate(SDS)and supercritical carbon dioxide(SC-CO2)were combined and modified to decellularize bovine cancellous bone(CB).After decellularization,almost 100%of A-Gal epitopes were removed,the combination of collagen,calcium and phosphate was reserved.The direct and indirect contact with macrophages was used to evaluate the cytotoxicity and immunological response of the materials.Mesenchymal stem cells(MSCs)were used in the in vitro cells’proliferation assay.The decellularized CB was proved has no cytotoxicity(grade 1)and no immunological response(NO,IL-2,IL-6 and TNF-α secretion inhibited),and could support MSCs proliferated continuedly.These results were similar to that of commercial decellularized human bone.This study suggests the potential of using this kind of combine decellularization process to fabricate heterogeneous ECM scaffolds for clinical application.

Donkey pericardium as a select sourcing to manufacture percutaneous heart valves:Decellularization has not yet demonstrated any clear cut advantage to glutaraldehyde treatment

Background:The donkey pericardium is considered a good candidate to manufacture percutaneous heart valves based upon its thinness,low cellularity and undulating collagen bundles and laminates.Decellularization represents an avenue worth exploring,should its superiority to glutaraldehyde-treated pericardium be demonstrated.Materials and methods:Donkey pericardium was divided into two groups:regular glutaraldehyde fixation and mild decellularization.The treated pericardia were observed using scanning electron microscopy,histology and transmission electron microscopy.Tensile tests were performed along the axial and perpendicular directions,with the data fitted into both the Gasser–Ogden–Holzapfel(GOH)material model and the Fung’s anisotropic one.Results:The microstructures of the pericardia processed by the two protocols were similar,showing collagen bundles and laminates free of flaws.The decellularization eliminated most of the cells,however leaving the structure somehow compressed.The collagen filaments in bundles were slightly blurry.The anisotropy rates of the non-decellularized specimens were almost identical to the decellularized ones.The decellularized pericardium appeared stiffer.Conclusion:The decellularization proved to be effective.However,it makes the tissue stiffer,which may lead to higher shear concentration during cardiac cycles and reduce its wavy microstructure.Therefore,it appears premature to select decellularized donkey pericardium to manufacture heart valves.

Deer antler stem cell niche: An interesting perspective

In recent years,there has been considerable exploration into methods aimed at enhancing the regenerative capacity of transplanted and/or tissue-resident cells.Biomaterials,in particular,have garnered significant interest for their potential to serve as natural scaffolds for cells.In this editorial,we provide commentary on the study by Wang et al,in a recently published issue of World J Stem Cells,which investigates the use of a decellularized xenogeneic extracellular matrix(ECM)derived from antler stem cells for repairing osteochondral defects in rat knee joints.Our focus lies specifically on the crucial role of biological scaffolds as a strategy for augmenting stem cell potential and regenerative capabilities,thanks to the establishment of a favorable microenvironment(niche).Stem cell differen-tiation heavily depends on exposure to intrinsic properties of the ECM,including its chemical and protein composition,as well as the mechanical forces it can generate.Collectively,these physicochemical cues contribute to a bio-instructive signaling environment that offers tissue-specific guidance for achieving effective repair and regeneration.The interest in mechanobiology,often conceptualized as a form of“structural memory”,is steadily gaining more validation and momen-tum,especially in light of findings such as these.

Preconditioning process for dermal tissue decellularization using electroporation with sonication

Decellularization to produce bioscaffolds composed of the extracellular matrix(ECM)uses enzymatic,chemical and physical methods to remove antigens and cellular components from tissues.Effective decellularization methods depend on the characteristics of tissues,and in particular,tissues with dense,complex structure and abundant lipid content are difficult to completely decellularize.Our study enables future research on the development of methods and treatments for fabricating bioscaffolds via decellularization of complex and rigid skin tissues,which are not commonly considered for decellularization to date as their structural and functional characteristics could not be preserved after severe decellularization.In this study,decellularization of human dermal tissue was done by a combination of both chemical(0.05%trypsin-EDTA,2%SDS and 1%Triton X-100)and physical methods(electroporation and sonication).After decellularization,the content of DNA remaining in the tissue was quantitatively confirmed,and the structural change of the tissue and the retention and distribution of ECM components were evaluated through histological and histochemical analysis,respectively.Conditions of the chemical pretreatment that increase the efficiency of physical stimulation as well as decellularization,and conditions for electroporation and sonication without the use of detergents,unlike the methods performed in previous studies,were established to enable the complete decellularization of the skin tissue.The combinatorial decellularization treatment formed micropores in the lipid bilayers of the skin tissues while removing all cell and cellular residues without affecting the ECM properties.Therefore,this procedure can be widely used to fabricate bioscaffolds by decellularizing biological tissues with dense and complex structures.

Polyethylene glycol crosslinked decellularized single liver lobe scaffolds with vascular endothelial growth factor promotes angiogenesis in vivo

Background: Improving the mechanical properties and angiogenesis of acellular scaffolds before transplantation is an important challenge facing the development of acellular liver grafts. The present study aimed to evaluate the cytotoxicity and angiogenesis of polyethylene glycol(PEG) crosslinked decellularized single liver lobe scaffolds(DLSs), and establish its suitability as a graft for long-term liver tissue engineering. Methods: Using mercaptoacrylate produced by the Michael addition reaction, DLSs were first modified using N-succinimidyl S-acetylthioacetate(SATA), followed by cross-linking with PEG as well as vascular endothelial growth factor(VEGF). The optimal concentration of agents and time of the individual steps were identified in this procedure through biomechanical testing and morphological analysis. Subsequently, human umbilical vein endothelial cells(HUVECs) were seeded on the PEG crosslinked scaffolds to detect the proliferation and viability of cells. The scaffolds were then transplanted into the subcutaneous tissue of Sprague-Dawley rats to evaluate angiogenesis. In addition, the average number of blood vessels was evaluated in the grafts with or without PEG at days 7, 14, and 21 after implantation. Results: The PEG crosslinked DLS maintained their three-dimensional structure and were more translucent after decellularization than native DLS, which presented a denser and more porous network structure. The results for Young’s modulus proved that the mechanical properties of 0.5 PEG crosslinked DLS were the best and close to that of native livers. The PEG-VEGF-DLS could better promote cell proliferation and differentiation of HUVECs compared with the groups without PEG cross-linking. Importantly, the average density of blood vessels was higher in the PEG-VEGF-DLS than that in other groups at days 7, 14, and 21 after implantation in vivo. Conclusions: The PEG crosslinked DLS with VEGF could improve the biomechanical properties of native DLS, and most importantly, their lack of cytotoxicity provides a new route to promote the proliferation of cells in vitro and angiogenesis in vivo in liver tissue engineering.

A decellularized nerve matrix scaffold inhibits neuroma formation in the stumps of transected peripheral nerve after peripheral nerve injury

Traumatic painful neuroma is an intractable clinical disease characterized by improper extracellular matrix(ECM)deposition around the injury site.Studies have shown that the microstructure of natural nerves provides a suitable microenvironment for the nerve end to avoid abnormal hyperplasia and neuroma formation.In this study,we used a decellularized nerve matrix scaffold(DNM-S)to prevent against the formation of painful neuroma after sciatic nerve transection in rats.Our results showed that the DNM-S effectively reduced abnormal deposition of ECM,guided the regeneration and orderly arrangement of axon,and decreased the density of regenerated axons.The epineurium-perilemma barrier prevented the invasion of vascular muscular scar tissue,greatly reduced the invasion ofα-smooth muscle actin-positive myofibroblasts into nerve stumps,effectively inhibited scar formation,which guided nerve stumps to gradually transform into a benign tissue and reduced pain and autotomy behaviors in animals.These findings suggest that DNM-S-optimized neuroma microenvironment by ECM remodeling may be a promising strategy to prevent painful traumatic neuromas.

Evaluation of novel decellularizing corneal stroma for cornea tissue engineering applications

AIM:To develop a new decellularization method depended upon the natural corneal structure and to harvest an ideal scaffold with good biocompatibilities for corneal reconstruction.METHODS:The acellular cornea matrix (ACM) were prepared from de-epithelium fresh porcine corneas (DFPCs) by incubation with 100% fresh human sera and additional electrophoresis at 4℃. Human corneal epithelial cells (HCEs) were used for the cytotoxicity tests of ACM. ACM were implanted into the Enhanced Green Fluorecence Protein (eGFP) transgenic mouse anterior chamber for evaluation of histocompatibility.RESULTS:HE and GSIB4 results showed fresh porcine cornea matrix with 100% human sera and electrophoresis could entirely decellularize stromal cell without reducing its transparency. ACM has no cytotoxic effect ex vivo. Animal test showed there was no rejection for one month after surgery.CONCLUSION:These results provide a decellularizing approach for the study of corneal tissue engineering and had the broader implications for the field of biological tissue engineering in other engineered organ or tissue matrix.

Therapeutic strategies for peripheral nerve injury: decellularized nerve conduits and Schwann cell transplantation

In recent years, the use of Schwann cell transplantation to repair peripheral nerve injury has attracted much attention. Animal-based studies show that the transplantation of Schwann cells in combination with nerve scaffolds promotes the repair of injured peripheral nerves. Autologous Schwann cell transplantation in humans has been reported recently. This article reviews current methods for removing the extracellular matrix and analyzes its composition and function. The development and secretory products of Schwann cells are also reviewed. The methods for the repair of peripheral nerve injuries that use myelin and Schwann cell transplantation are assessed. This survey of the literature data shows that using a decellularized nerve conduit combined with Schwann cells represents an effective strategy for the treatment of peripheral nerve injury. This analysis provides a comprehensive basis on which to make clinical decisions for the repair of peripheral nerve injury.

Repair of a common bile duct defect with a decellularized ureteral graft

AIM To evaluate the feasibility of repairing a common bile duct defect with a decellularized ureteral graft in a porcine model.METHODS Eighteen pigs were randomly divided into three groups. An approximately 1 cm segment of the common bile duct was excised from all the pigs. The defect was repaired using a 2 cm long decellularized ureteral graft over a T-tube(T-tube group, n = 6) or a silicone stent(stent group, n = 6). Six pigs underwent bile duct reconstruction with a graft alone(stentless group). The surviving animals were euthanized at 3 mo. Specimens of the common bile ducts were obtained for histological analysis.RESULTS The animals in the T-tube and stent groups survived until sacrifice. The blood test results were normal in both groups. The histology results showed a biliary epithelial layer covering the neo-bile duct. In contrast, all the animals in the stentless group died due to biliary peritonitis and cholangitis within two months post-surgery. Neither biliary epithelial cells nor accessory glands were observed at the graft sites in the stentless group.CONCLUSION Repair of a common bile duct defect with a decellularized ureteral graft appears to be feasible. A T-tube or intraluminal stent was necessary to reduce postoperative complications.

Differentiation of human embryonic stem cells derived mesenchymal stem cells into corneal epithelial cells after being seeded on decellularized SMILE-derived lenticules

AIM: To evaluate the feasibility of mesenchymal stem cells(MSCs) to differentiate into corneal epithelial cells after being seeded on the decellularized small incision lenticule extraction(SMILE)-derived lenticules. METHODS: The fresh lenticules procured from patients undergoing SMILE for the correction of myopia were decellularized. The MSCs were subsequently cultivated on those denuded lenticules. The MSCs without lenticules were used as a control. The proliferation activity of the MSCs after seeding 24 h was quantitatively determined with the Cell Counting Kit-8(CCK-8) assay. Immunofluorescence staining and quantitative reverse transcription polymerase chain reaction(qRT-PCR) were used to assess the marker expression in differentiated MSCs. RESULTS: The data showed that both fresh and decellularized lenticules could significantly promote the proliferation of MSCs, compared to that in control(P=0.02 for fresh lenticules, P=0.001 for decellularize ones, respectively). The MSCs seeded on both lenticules were positive for cytokeratin 3(CK3) staining. The expression of CK3 increased 5-fold in MSCs seeded on fresh lenticules and 18-fold on decellularized ones, compared to that in control. There was a significant difference in the expression of CK3 in MSCs seeded on fresh and decellularized lenticules(P<0.001). The expression of CK8 and CK18 was similar in pure MSCs and MSCs seeded on fresh lenticules(P>0.05), while the expression of these markers was decreased in MSCs seeded on decellularized ones. CONCLUSION: These results suggest that the decellularized lenticules might be more suitable for MSCs to differentiate into corneal epithelial cells, which offersthe prospect of a novel therapeutic modality of SMILEderived lenticules in regenerative corneal engineering.

Decellularized adipose matrix provides an inductive microenvironment for stem cells in tissue regeneration

Stem cells play a key role in tissue regeneration due to their self-renewal and multidirectional differentiation,which are continuously regulated by signals from the extracellular matrix(ECM)microenvironment.Therefore,the unique biological and physical characteristics of the ECM are important determinants of stem cell behavior.Although the acellular ECM of specific tissues and organs(such as the skin,heart,cartilage,and lung)can mimic the natural microenvironment required for stem cell differentiation,the lack of donor sources restricts their development.With the rapid development of adipose tissue engineering,decellularized adipose matrix(DAM)has attracted much attention due to its wide range of sources and good regeneration capacity.Protocols for DAM preparation involve various physical,chemical,and biological methods.Different combinations of these methods may have different impacts on the structure and composition of DAM,which in turn interfere with the growth and differentiation of stem cells.This is a narrative review about DAM.We summarize the methods for decellularizing and sterilizing adipose tissue,and the impact of these methods on the biological and physical properties of DAM.In addition,we also analyze the application of different forms of DAM with or without stem cells in tissue regeneration(such as adipose tissue),repair(such as wounds,cartilage,bone,and nerves),in vitro bionic systems,clinical trials,and other disease research.

Morphology of spinal cord extracellular matrix-derived acellular scaffolds fabricated in rats

Acellular peripheral allograft scaffolds can be fabricated using chemical extraction techniques,but methods for producing acellular scaffold derived from spinal cord tissue are not currently available.The present study demonstrated that chemical extraction using Triton X-100 and sodium deoxycholate could be used to completely remove the cells,axons and neural sheaths in spinal cord extracellular matrix-derived scaffolds.The matrix fibers were longitudinally arranged in a wave-like formation,and were connected by fiber junctions.Lattice-shaped fiber cages appeared and developed into bone trabecula-like changes.The natural structure of matrix fibers in the scaffolds was maintained;this helps to guide the differentiation and migration of implanted stem cells.Decellularized spinal cord extracellular matrix-derived scaffolds can provide an ideal substance for fabricating tissue-engineered spinal cord.

A Novel Low Air Pressure-Assisted Approach for the Construction of Cells-Decellularized Tendon Scaffold Complex

Objective The goal of this study was to develop a decellularized tendon scaffold(DTS)and repopulate it with adipose-derived stem cells(ADSCs)assisted by low air pressure(LP).Methods The porcine superficial flexor tendons were processed into the DTSs using a combination of physical,chemical,and enzymatic treatments.The effectiveness of decellularization was verified by histological analysis and DNA quantification.The properties of the DTSs were evaluated by quantitative analysis of biochemical characterization,porosimetry,in vitro biocompatibility assessment,and biomechanical testing.Subsequently,the ADSCs-DTS complexes were constructed via cell injection assisted by LP or under atmospheric pressure.The differences in cell distribution,biomechanical properties,and the total DNA content were compared by histological analysis,biomechanical testing,and DNA quantification,respectively.Results Histological analysis confirmed that no cells or condensed nuclear materials were retained within the DTSs with widened interfibrillar space.The decellularization treatment resulted in a significant decrease in the content of DNA and glycosaminoglycans,and a significant increase in the porosity.The DTSs were cytocompatible in vitro and did not show reduced collagen content and inferior biomechanical properties compared with the fresh-frozen tendons.The assistance of LP promoted the broader distribution of cells into the adjacent interfibrillar space and cell proliferation in DTSs.The biomechanical properties of the scaffolds were not significantly affected by the recellularization treatments.Conclusion A novel LP-assisted approach for the construction of cells-DTS complex was established,which could be a methodological foundation for further bioreactor and in vitro studies.

Relevance of Protein Content within the Renal Scaffold for Kidney Bioengineering and Regeneration

Chronic kidney disease is currently a major public health problem around the world. Although hemodialysis increases survival of patients with end-stage renal disease, kidney transplantation remains the only potentially curative treatment. However, transplantation as a therapeutic option is limited by availability of suitable donor organs. This situation highlights the urgent need to find new and potentially inexhaustible sources of transplantable organs. Perfusion decellularizarion of whole organs is a novel approach to organ engineering and regeneration. In the present research, we used a continuous perfusion decellularization protocol to eliminate cellular componet of kidney and evaluated residual scaffold components after decellularizarion process by proteomics analysis. Our proteomic data show that this protocol results in incomplete removal of cellular proteins. However, unlike other authors, we assume that proteins retained within decellularized kidney scaffold could be the basis for specific homing and celular differentation in the recellularization process.

Study on the Preparation of Decellularized Scaffold of Bovine Pericardium

Objective: To search for the best procedure on preparation of acellular bovine pericardium,so to provide scaffolds for constructing tissue-engineering. Methods: The bovine pericardiums were treated with 5 methods, which were divided into 6 groups.Group A: Fresh bovine pericardium; Group B: Trypsin-detergent group;Group C: Freeze-thaw-detergent 24 h group; Group D: Freeze-thaw-detergent 48 h group; Group E: Freeze-thaw-nuclease group; Group F: Detergent-nuclease group. Then, by HE staining and scanning electron microscope to observe the effects of decellularization and fibrous changes among the 6 groups; by water content testing,mechanical testing to observe the changes in physical properties of the matrix; by detecting the DNA content of each group to determine the effect of decellularization qualitatively; by cytotoxicity test to detect the biocompatibility of bovine pericardium in each group. Results: The 5 methods can all remove the cellular components effectively, compared with the fresh bovine pericardium,the water content of each decellularized group were increased(P<0.05), while the DNA content decreased(P<0.05), with statistically significant differences. Of group E, the fibers were a little disorder, with the largest tension and the elastic modulus increased, while the rupture tensile rate decreased. Compared with fresh bovine pericardium,the largest tension of the other decellularization groups were all decreased(P<0.05). The fibers of group B, group D were irregularly arranged and also with ruptures, both the elastic modulus and the rupture tensile rate decreased(P<0.05). In group C and F, the fibers were dense and their direction was normal, the elastic modulus and the rupture tensile rate were similar to the fresh bovine pericardium(P>0.05). Cytotoxicity results showed that the cell toxicity of group B, group C, group D, group E and group F were respectively 0.9, 0.6, 1.0, 1.0 and 0.5, each group were qualified toxicity test, in which group C and group F were with the lowest cytotoxicity. Conclusion: Group C and group F can remove the cell components of bovine pericardium successfully,while maintaining the major structural components and the histological and biological properties of bovine pericardium,and with low cytotoxicity.However, group C is more economical than group F,and easier to operate. So the method on freeze-thaw-detergent 24 h can be the best choice to produce a decellularized bovine pericardium.

Decellularized sciatic nerve matrix as a biodegradable conduit for peripheral nerve regeneration

The use of autologous nerve grafts remains the gold standard for treating nerve defects, but current nerve repair techniques are limited by donor tissue availability and morbidity associated with tissue loss. Recently, the use of conduits in nerve injury repair, made possible by tissue engineering, has shown therapeutic potential. We manufactured a biodegradable, collagen-based nerve conduit containing decellularized sciatic nerve matrix and compared this with a silicone conduit for peripheral nerve regeneration using a rat model. The collagen-based conduit contains nerve growth factor, brain-derived neurotrophic factor, and laminin, as demonstrated by enzyme-linked immunosorbent assay. Scanning electron microscopy images showed that the collagen-based conduit had an outer wall to prevent scar tissue infiltration and a porous inner structure to allow axonal growth. Rats that were implanted with the collagen-based conduit to bridge a sciatic nerve defect experienced significantly improved motor and sensory nerve functions and greatly enhanced nerve regeneration compared with rats in the sham control group and the silicone conduit group. Our results suggest that the biodegradable collagen-based nerve conduit is more effective for peripheral nerve regeneration than the silicone conduit.