Optimizing Decellularization Strategies for the Efficient Production of Whole Rat Kidney Scaffolds

Enhancing epithelial regeneration with gelatin methacryloyl hydrogel loaded with extracellular vesicles derived from adipose mesenchymal stem cells for decellularized tracheal patching

Patch tracheoplasty offers an alternative approach to repairing congenital tracheal stenosis without tension but poses a higher risk of restenosis, granulation tissue formation, and tracheal collapse. The use of tissue-engineered patches for tracheoplasty has been proposed as a solution. Studies suggest that decellularization methods are effective in preparing tracheal patches; however, further research is necessary to improve their efficiency and safety. This study introduces a novel decellularization method using 3-[(3Cholamidopropyl)dimethylammonio]propanesulfonate (CHAPS) and DNase to create a biocompatible tracheal matrix. To enhance the regeneration of epithelial regions within decellularized tracheal scaffolds, this study conducted experimental validations at various levels, both in vivo and in vitro, by introducing extracellular vesicles derived from adipose mesenchymal stem cells as an intervention measure. The ability to promote epithelial regeneration was validated both in vitro and in vivo by incorporating a GelMA hydrogel loaded with adipose-derived mesenchymal stem cell extracellular vesicles (ADMSC-EVs). Evaluation of HBE cell proliferation on tracheal patches treated with varying concentrations of ADMSC-EVs, along with migration and invasion experiments on ADMSC-EV-treated HBE cells, demonstrated enhanced epithelialization in vitro. The inflammatory response and vascular regeneration were assessed via subcutaneous implantation in rats for two weeks. In a rabbit tracheal defect model, the hydrogel loaded with ADMSC-EVs accelerated re-epithelialization in the patch area. This approach shows promise as a novel material for tracheal patching in clinical applications.

Evaluation of decellularized sheep kidney scaffolds for renal tissue engineering: Biocompatibility and stem cell differentiation potential

Tissue engineering (TE) combines scaffolds, cells, and bioactive chemicals in order to create tissues. The objective is to restore or sustain tissue functionality and expedite the recovery of damaged tissues or organs in a controlled laboratory environment. This study aimed to evaluate the properties and biocompatibility of decellularized sheep kidney scaffolds (DKS) and to explore the differentiation potential of adipose-derived mesenchymal stem cells (ADSCs) into renal cells. After decellularizing sheep kidneys using freeze-drying and detergent techniques, we conducted histological studies, DNA quantification, and ultrastructural evaluations using scanning electron microscopy (SEM). Furthermore, to assay the feasibility and attachment of stem cells to the decellularized scaffolds, ADSCs were cultured on the scaffolds and subjected to the MTT assay. The expression of the pax2 gene was analyzed using real-time PCR to determine the differentiation of MSCs into kidney cells. DNA quantitation revealed a significant reduction in the quantity of DNA present in the scaffold tissue compared to the control kidney tissue. Ultrastructural examination confirmed the preservation of the decellularized scaffold's ultrastructure. Histological analysis demonstrated the complete removal of nuclear material from the scaffold. Additionally, Pax2 gene expression was significantly increased in ADSC cells cultured on the scaffold compared to the control group. The results demonstrate that the produced scaffolds are well-suited for regenerative medicine, exhibiting excellent biocompatibility and providing a conducive environment for the differentiation of ADSCs.

Efficient Decellularization of the Full-Thickness Rat-Derived Abdominal Wall to Produce Acellular Biologic Scaffolds for Tissue Reconstruction: Promising Evidence Acquired from In Vitro Results

BACKGROUND

Functional restoration of abdominal wall defects represents one of the fundamental challenges of reconstructive surgery. Synthetic grafts or crosslinked animal-derived biological grafts are characterized by significant adverse reactions, which are mostly observed after their implantation. The aim of this study was to evaluate the efficacy of the decellularization protocol to produce a completely acellular full-thickness abdominal wall scaffold.

METHODS

Full-thickness abdominal wall samples were harvested from Wistar rats and submitted to a three-cycle decellularization process. Histological, biochemical, and DNA quantification analyses were applied to evaluate the effect of the decellularization protocol. Mechanical testing and immunogenicity assessment were also performed.

RESULTS

Histological, biochemical, and DNA analysis results showed efficient decellularization of the abdominal wall samples after the third cycle. Decellularized abdominal wall scaffolds were characterized by good biochemical and mechanical properties.

CONCLUSION

The data presented herein confirm the effective production of a rat-derived full-thickness abdominal wall scaffold. Expanding this approach will allow the exploitation of the capacity of the proposed decellularization protocol in producing acellular abdominal wall scaffolds from larger animal models or human cadaveric donors. In this way, the utility of biological scaffolds with preserved in vivo remodeling properties may be one step closer to its application in clinical studies.

Progress of 3D Bioprinting in Organ Manufacturing

Three-dimensional (3D) bioprinting is a family of rapid prototyping technologies, which assemble biomaterials, including cells and bioactive agents, under the control of a computer-aided design model in a layer-by-layer fashion. It has great potential in organ manufacturing areas with the combination of biology, polymers, chemistry, engineering, medicine, and mechanics. At present, 3D bioprinting technologies can be used to successfully print living tissues and organs, including blood vessels, skin, bones, cartilage, kidney, heart, and liver. The unique advantages of 3D bioprinting technologies for organ manufacturing have improved the traditional medical level significantly. In this article, we summarize the latest research progress of polymers in bioartificial organ 3D printing areas. The important characteristics of the printable polymers and the typical 3D bioprinting technologies for several complex bioartificial organs, such as the heart, liver, nerve, and skin, are introduced.