Journal of Tissue Engineering最新文献

Impaired wound healing poses a significant burden on the healthcare system and patients. Stem cell therapy has demonstrated promising potential in the treatment of wounds. However, its clinical application is hindered by the low efficiency of cell homing. In this study, we successfully integrated P-selectin glycoprotein ligand-1 (PSGL-1) into the genome of human adipose-derived mesenchymal stem cells (ADSCs) using a Cas9-AAV6-based genome editing tool platform. Our findings revealed that PSGL-1 knock-in enhanced the binding of ADSCs to platelets and their adhesion to the injured site. Moreover, the intravenous infusion of PSGL-1 -engineered ADSCs (KI-ADSCs) significantly improved the homing efficiency and residence rate at the site of skin lesions in mice. Mechanistically, PSGL-1 knock-in promotes the release of some therapeutic cytokines by activating the canonical WNT/β-catenin signaling pathway and accelerates the healing of wounds by promoting angiogenesis, re-epithelialization, and granulation tissue formation at the wound site. This study provides a novel strategy to simultaneously address the problem of poor migration and adhesion of mesenchymal stem cells (MSCs).

Our prior research has effectively developed tissue-engineered vascularized oral mucosa equivalents (VOME); however, challenges such as low repeatability and stability, as well as the inability to accurately replicate the complexity of real blood vessels, were encountered. Therefore, this study aimed to screen the VOME and native oral mucosa vascular homeostasis phenotypes by tandem mass tag-tagged proteomics associated with laser capture microdissection and human angiogenesis antibody array technology. Then, lentiviruses were constructed and stably transfected with vascular endothelial-like cells (VELCs) to detect angiogenic capacity. HE, EdU Apollo tracer staining, immunofluorescence staining, scanning electron microscopy, biomechanical testing, and a small animal ultrasound imaging system were used to analyze the characteristics of vascularization homeostasis and monitor functional regeneration of the vascularized homeostatic phenotypic oral mucosal equivalents (VHPOME). The results showed that PGAM1, COL5A1, ANG, and RNH1 are potential specific angiogenesis phenotypes. High expression of PGAM1, COL5A1, and ANG and/or low expression of RNH1 can promote the angiogenesis of VOME. ANG/shRNH1 has the most significant tube-like structure-formation ability. The expression of PGAM1, COL5A1, and ANG in the VHPOME group was higher than that of the control group, and the expression of RNH1 was lower than that of the control group. COL5A1/ANG can significantly improve the mechanical properties. The blood flow signal was most significant in the ANG/shRNH1 group. PGAM1, COL5A1, ANG, shRNH1, PGAM1/ANG, COL5A1/ANG, PGAM1/shRNH1, PGAM1/shRNH1, COL5A1/shRNH1, and ANG/shRNH1 may be the targets for establishing vascularization homeostasis and functional regeneration of oral mucosal equivalent genes (groups), and ANG/shRNH1 has the most significant effect.

Articular cartilage defect therapy is still dissatisfactory in clinic. Direct cell implantation faces challenges, such as tumorigenicity, immunogenicity, and uncontrollability. Extracellular vesicles (EVs) based cell-free therapy becomes a promising alternative approach for cartilage regeneration. Even though, EVs from different cells exhibit heterogeneous characteristics and effects. The aim of the study was to discover the functions of EVs from the cells during chondrogenesis timeline on cartilage regeneration. Here, bone marrow mesenchymal stem cells (BMSCs)-EVs, juvenile chondrocytes-EVs, and adult chondrocytes-EVs were used to represent the EVs at different differentiation stages, and fibroblast-EVs as surrounding signals were also joined to compare. Fibroblasts-EVs showed the worst effect on chondrogenesis. While juvenile chondrocyte-EVs and adult chondrocyte-EVs showed comparable effect on chondrogenic differentiation as BMSCs-EVs, BMSCs-EVs showed the best effect on cell proliferation and migration. Moreover, the amount of EVs secreted from BMSCs were much more than that from chondrocytes. An injectable decellularized extracellular matrix (dECM) hydrogel from small intestinal submucosa (SIS) was fabricated as the EVs delivery platform with natural matrix microenvironment. In a rat model, BMSCs-EVs loaded SIS hydrogel was injected into the articular cartilage defects and significantly enhanced cartilage regeneration in vivo. Furthermore, protein proteomics revealed BMSCs-EVs specifically upregulated multiple metabolic and biosynthetic processes, which might be the potential mechanism. Thus, injectable SIS hydrogel loaded with BMSCs-EVs might be a promising therapeutic way for articular cartilage defect.

Traumatic injuries to the peripheral nervous system (PNI) can lead to severe consequences such as paralysis. Unfortunately, current treatments rarely allow for satisfactory functional recovery. The high healthcare costs associated with PNS injuries, worker disability, and low patient satisfaction press for alternative solutions that surpass current standards. For the treatment of injuries with a deficit of less than 30 mm to bridge, the use of synthetic nerve conduits (NGC) is favored. However, to develop such promising therapeutic strategies, in vitro models that more faithfully mimic nerve physiology are needed. The absence of a clinically scaled model with essential elements such as a three-dimension environment and dynamic coculture has hindered progress in this field. The presented research focuses on the development of an in vitro coculture model of the peripheral nervous system (PNS) involving the use of functional biomaterial which microstructure replicates nerve topography. Initially, the behavior of neuron-derived cell lines (N) and Schwann cells (SC) in contact with a short section of biomaterial (5 mm) was studied. Subsequent investigations, using fluorescent markers and survival assays, demonstrated the synergistic effects of coculture. These optimized parameters were then applied to longer biomaterials (30 mm), equivalent to clinically used NGC. The results obtained demonstrated the possibility of maintaining an extended coculture of SC and N over a 7-day period on a clinically scaled biomaterial, observing some functionality. In the long term, the knowledge gained from this work will contribute to a better understanding of the PNS regeneration process and promote the development of future therapeutic approaches while reducing reliance on animal experimentation. This model can be used for drug screening and adapted for personalized medicine trials. Ultimately, this work fills a critical gap in current research, providing a transformative approach to study and advance treatments for PNS injuries.

The incidence of ulcerative colitis (UC) is rapidly rising worldwide. Oral drug delivery system is a promising approach for treating UC, but it often fails to accumulate to the inflammatory lesions, thus, it is impressive to develop a colon-targeted oral delivery system for preventing systemic toxicity and maintaining UC therapeutics. Here, a negative-charged PLGA nanoparticle system was designed to encapsulate celastrol (Cel), and then chitosan and mannose were coated on the surface of the nanoparticles (MC@Cel-NPs) to endow these nanoparticles with the mucosal adsorption and macrophage targeting abilities. MC@Cel-NPs demonstrate excellent resist decomposition ability against the strong acidic gastrointestinal environment, and accumulates in the specific inflammatory sites through the affinity of electrostatic reaction. After releasing the payload, MC@Cel-NPs could remarkably alleviate the colon inflammation, which was evidenced by the decrease in pro-inflammatory cytokines TNF-α, IL-1β, and IL-6 in both blood and colon sections, and scavenging reactive oxygen species (ROS) in colon cells, including macrophage, neutrophil, T cell, and B cell. This nanoparticle system provided a new approach for treating UC through a Chinese herbal ingredient-related oral delivery manner.

Antifibrotic drug screening requires evaluating the inhibitory effects of drug candidates on fibrotic cells while minimizing any adverse effects on normal cells. It is challenging to create organ-specific vascularized organoids that accurately model fibrotic and normal tissues for drug screening. Our previous studies have established methods for culturing primary microvessels and epithelial cells from adult tissues. In this proof-of-concept study, we used rats as a model organism to create a two-dimensional vascularized liver organoid model that comprised primary microvessels, epithelia, and stellate cells from adult livers. To provide appropriate substrates for cell culture, we engineered ECMs with defined stiffness to mimic the different stages of fibrotic tissues and normal tissues. We examined the effects of two TGFβ signaling inhibitors, A83-01 and pirfenidone, on the vascularized liver organoids on the stiff and soft ECMs. We found that A83-01 inhibited fibrotic markers while promoting epithelial genes of hepatocytes and cholangiocytes. However, it inhibited microvascular genes on soft ECM, indicating a detrimental effect on normal tissues. Furthermore, A83-01 significantly promoted the expression of markers of stem cells and cancers, increasing the potential risk of it being a carcinogen. In contrast, pirfenidone, an FDA-approved compound for antifibrotic treatments, did not significantly affect all the genes examined on soft ECM. Although pirfenidone had minor effects on most genes, it did reduce the expression of collagens, the major components of fibrotic tissues. These results explain why pirfenidone can slow fibrosis progression with minor side effects in clinical trials. In conclusion, our study presents a method for creating vascularized liver organoids that can accurately mimic fibrotic and normal tissues for drug screening. Our findings provide valuable insights into the potential risks and benefits of using A83-01 and pirfenidone as antifibrotic drugs. This method can be applied to other organs to create organ-specific vascularized organoids for drug development.

Diabetic wound healing presents a significant clinical challenge due to the interplay of systemic metabolic disturbances and local inflammation, which hinder the healing process. Macrophages undergo a phenotypic shift from M1 to M2 during wound healing, a transition pivotal for effective tissue repair. However, in diabetic wounds, the microenvironment disrupts this phenotypic polarization, perpetuating inflammation, and impeding healing. Reprograming macrophages to restore their M2 phenotype offers a potential avenue for modulating the wound immune microenvironment and promoting healing. This review elucidates the mechanisms underlying impaired macrophage polarization toward the M2 phenotype in diabetic wounds and discusses novel strategies, including epigenetic and metabolic interventions, to promote macrophage conversion to M2. Hydrogels, with their hydrated 3D cross-linked structure, closely resemble the physiological extracellular matrix and offer advantageous properties such as biocompatibility, tunability, and versatility. These characteristics make hydrogels promising candidates for developing immunomodulatory materials aimed at addressing diabetic wounds. Understanding the role of hydrogels in immunotherapy, particularly in the context of macrophage reprograming, is essential for the development of advanced wound care solutions. This review also highlights recent advancements in immunotherapeutic hydrogels as a step toward precise and effective treatments for diabetic wounds.