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.

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.

Bioreactor for the reconstitution of a decellularized vascular matrix of biological origin

Acellular matrices derived from animal and human cadaveric donor vessels or other tubular matrices are appropriate candidates for the creation of tissue- en-gineered, small-diameter, muscular arteries. Engi-neering principles have been used to design a bio-reactor and the necessary auxiliary systems for the reconstitution of a previously decellularized vascular matrix. The bioreactor enables the attachment of cells to the luminal and/or exterior surfaces of the matrix. For the recellularization procedure, the matrix is situated within a sealed compartment in order to maintain a sterile environment. The matrix is rotated continuously to assure a spatially uniform re-constitution. The auxiliary systems that serve the bioreactor are: (a) an oxygenator, (b) peristaltic pumps, one for conveying the internal cell medium and the other for conveying the external cell medium, (c) motor and gearing to create steady and controlled rotation, (d) reservoirs for the containment of the two media, and (e) tubing to convey the respective fluids and to interconnect the bioreactor culture chamber to the various auxiliary components. A recellularized matrix produced by the bioreactor demonstrated its capabilities to reconstitute a previously decellularized scaffold.

Decellularized extracellular matrix scaffolds:Recent trends and emerging strategies in tissue engineering

The application of scaffolding materials is believed to hold enormous potential for tissue regeneration.Despite the widespread application and rapid advance of several tissue-engineered scaffolds such as natural and synthetic polymer-based scaffolds,they have limited repair capacity due to the difficulties in overcoming the immunogenicity,simulating in-vivo microenvironment,and performing mechanical or biochemical properties similar to native organs/tissues.Fortunately,the emergence of decellularized extracellular matrix(dECM)scaffolds provides an attractive way to overcome these hurdles,which mimic an optimal non-immune environment with native three-dimensional structures and various bioactive components.The consequent cell-seeded construct based on dECM scaffolds,especially stem cell-recellularized construct,is considered an ideal choice for regenerating functional organs/tissues.Herein,we review recent developments in dECM scaffolds and put forward perspectives accordingly,with particular focus on the concept and fabrication of decellularized scaffolds,as well as the application of decellularized scaffolds and their combinations with stem cells(recellularized scaffolds)in tissue engineering,including skin,bone,nerve,heart,along with lung,liver and kidney.

Generation of functional organs from stem cells

We are now well entering the exciting era of stem cells.Potential stem cell therapy holds great promise for the treatment of many diseases such as stroke,traumatic brain injury,Alzheimer’s disease,Parkinson’s disease,amyotrophic lateral-sclerosis,myocardial infarction,muscular dystrophy,diabetes,and etc..It is generally believed that transplantation of specific stem cells into the injured tissue to replace the lost cells is an effective way to repair the tissue.In fact,organ transplantation has been successfully practiced in clinics for liver or kidney failure.However,the severe shortage of donor organs has been a major obstacle for the expansion of organ transplantation programs.Toward that direction,generation of transplantable organs using stem cells is a desirable approach for organ replacement and would be of great interest for both basic and clinical scientists.Here we review recent progress in the field of organ generation using various methods including single adult tissue stem cells,a blastocyst complementation system,tissue decellularization/recellularization and a combination of stem cells and tissue engineering.