Polymeric Gelatin Scaffolds Affect Mesenchymal Stem Cell Differentiation and Its Diverse Applications in Tissue Engineering

Advances in Treatments for Epidermolysis Bullosa (EB): Emphasis on Stem Cell-Based Therapy

Epidermolysis bullosa (EB) is a rare genetic dermatosis characterized by skin fragility and blister formation. With a wide phenotypic spectrum and potential extracutaneous manifestations, EB poses significant morbidity and mortality risks. Currently classified into four main subtypes based on the level of skin cleavage, EB is caused by genetic mutations affecting proteins crucial for maintaining skin integrity. The management of EB primarily focuses on preventing complications and treating symptoms through wound care, pain management, and other supportive measures. However, recent advancements in the fields of stem cell therapy, tissue engineering, and gene therapy have shown promise as potential treatments for EB. Stem cells capable of differentiating into skin cells, have demonstrated positive outcomes in preclinical and early clinical trials by promoting wound healing and reducing inflammation. Gene therapy, on the other hand, aims to correct the underlying genetic defects responsible for EB by introducing functional copies of mutated genes or modifying existing genes to restore protein function. Particularly for severe subtypes like Recessive Dystrophic Epidermolysis Bullosa (RDEB), gene therapy holds significant potential. This review aims to evaluate the role of new therapeutic approaches in the treatment of EB. The review includes findings from studies conducted on humans. While early studies and clinical trials have shown promising results, further research and trials are necessary to establish the safety and efficacy of these innovative approaches for EB treatment.

Emerging Strategies in Mesenchymal Stem Cell-Based Cardiovascular Therapeutics

Cardiovascular diseases continue to challenge global health, demanding innovative therapeutic solutions. This review delves into the transformative role of mesenchymal stem cells (MSCs) in advancing cardiovascular therapeutics. Beginning with a historical perspective, we trace the development of stem cell research related to cardiovascular diseases, highlighting foundational therapeutic approaches and the evolution of cell-based treatments. Recognizing the inherent challenges of MSC-based cardiovascular therapeutics, which range from understanding the pro-reparative activity of MSCs to tailoring patient-specific treatments, we emphasize the need to refine the pro-regenerative capacity of these cells. Crucially, our focus then shifts to the strategies of the fourth generation of cell-based therapies: leveraging the secretomic prowess of MSCs, particularly the role of extracellular vesicles; integrating biocompatible scaffolds and artificial sheets to amplify MSCs' potential; adopting three-dimensional ex vivo propagation tailored to specific tissue niches; harnessing the promise of genetic modifications for targeted tissue repair; and institutionalizing good manufacturing practice protocols to ensure therapeutic safety and efficacy. We conclude with reflections on these advancements, envisaging a future landscape redefined by MSCs in cardiovascular regeneration. This review offers both a consolidation of our current understanding and a view toward imminent therapeutic horizons.

Advances in natural and synthetic macromolecules with stem cells and extracellular vesicles for orthopedic disease treatment

Serious orthopedic disorders resulting from myriad diseases and impairments continue to pose a considerable challenge to contemporary clinical care. Owing to its limited regenerative capacity, achieving complete bone tissue regeneration and complete functional restoration has proven challenging with existing treatments. By virtue of cellular regenerative and paracrine pathways, stem cells are extensively utilized in the restoration and regeneration of bone tissue; however, low survival and retention after transplantation severely limit their therapeutic effect. Meanwhile, biomolecule materials provide a delivery platform that improves stem cell survival, increases retention, and enhances therapeutic efficacy. In this review, we present the basic concepts of stem cells and extracellular vesicles from different sources, emphasizing the importance of using appropriate expansion methods and modification strategies. We then review different types of biomolecule materials, focusing on their design strategies. Moreover, we summarize several forms of biomaterial preparation and application strategies as well as current research on biomacromolecule materials loaded with stem cells and extracellular vesicles. Finally, we present the challenges currently impeding their clinical application for the treatment of orthopedic diseases. The article aims to provide researchers with new insights for subsequent investigations.

Probiotic cultivated meat: bacterial-based scaffolds and products to improve cultivated meat

Cultivated meat is emerging to replace traditional livestock industries, which have ecological costs, including land and water overuse and considerable carbon emissions. During cultivated meat production, mammalian cells can increase their numbers dramatically through self-renewal/proliferation and transform into mature cells, such as muscle or fat cells, through maturation/differentiation. Here, we address opportunities for introducing probiotic bacteria into the cultivated meat industry, including using them to produce renewable antimicrobials and scaffolding materials. We also offer solutions to challenges, including the growth of bacteria and mammalian cells, the effect of probiotic bacteria on production costs, and the effect of bacteria and their products on texture and taste. Our summary provides a promising framework for applying microbial composites in the cultivated meat industry.

The progressive trend of modeling and drug screening systems of breast cancer bone metastasis

Bone metastasis is considered as a considerable challenge for breast cancer patients. Various in vitro and in vivo models have been developed to examine this occurrence. In vitro models are employed to simulate the intricate tumor microenvironment, investigate the interplay between cells and their adjacent microenvironment, and evaluate the effectiveness of therapeutic interventions for tumors. The endeavor to replicate the latency period of bone metastasis in animal models has presented a challenge, primarily due to the necessity of primary tumor removal and the presence of multiple potential metastatic sites.The utilization of novel bone metastasis models, including three-dimensional (3D) models, has been proposed as a promising approach to overcome the constraints associated with conventional 2D and animal models. However, existing 3D models are limited by various factors, such as irregular cellular proliferation, autofluorescence, and changes in genetic and epigenetic expression. The imperative for the advancement of future applications of 3D models lies in their standardization and automation. The utilization of artificial intelligence exhibits the capability to predict cellular behavior through the examination of substrate materials' chemical composition, geometry, and mechanical performance. The implementation of these algorithms possesses the capability to predict the progression and proliferation of cancer. This paper reviewed the mechanisms of bone metastasis following primary breast cancer. Current models of breast cancer bone metastasis, along with their challenges, as well as the future perspectives of using these models for translational drug development, were discussed.

Fabrication of Rosuvastatin-Incorporated Polycaprolactone -Gelatin Scaffold for Bone Repair: A Preliminary In Vitro Study

OBJECTIVE

Rosuvastatin (RSV) is a hydrophilic, effective statin with a long half-life that stimulates bone regeneration. The present study aims to develop a new scaffold and controlled release system for RSV with favourable properties for bone tissue engineering (BTE).

MATERIALS AND METHODS

In this experimental study, high porous polycaprolactone (PCL)-gelatin scaffolds that contained different concentrations of RSV (0 mg/10 ml, 0.1 mg/10 ml, 0.5 mg/10 ml, 2.5 mg/10 ml, 12.5 mg/10 ml, and 62.5 mg/10 ml) were fabricated by the thermally-induced phase separation (TIPS) method. Mechanical and biological properties of the scaffolds were evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), compressive strength, porosity, MTT, alkaline phosphatase (ALP) activity, water contact angle, degradation rate, pH alteration, blood clotting index (BCI), and hemocompatibility.

RESULTS

SEM analysis confirmed that the porous structure of the scaffolds contained interconnected pores. FTIR results showed that the RSV structure was maintained during the scaffold's fabrication. RSV (up to 62.5 mg/10 ml) increased compressive strength (16.342 ± 1.79 MPa), wettability (70.2), and degradation rate of the scaffolds. Scaffolds that contained 2.5 mg/10 ml RSV had the best effect on the human umbilical cord mesenchymal stem cell (HUC-MSCs) survival, hemocompatibility, and BCI. As a sustained release system, only 31.68 ± 0.1% of RSV was released from the PCL-Gelatin-2.5 mg/10 ml RSV scaffold over 30 days. In addition, the results of ALP activity showed that RSV increased the osteogenic differentiation potential of the scaffolds.

CONCLUSION

PCL-Gelatin-2.5 mg/10 ml RSV scaffolds have favorable mechanical, physical, and osteogenic properties for bone tissue and provide a favorable release system for RSV. They can mentioned as a a promising strategy for bone regeneration that should be further assessed in animals and clinical studies.

Multifunctional magnetocaloric bone cement with a time-varying alkaline microenvironment for sequential bacterial inhibition, angiogenesis and osteogenesis

Repairing infected bone defects remains a severe challenge due to antibiotic abuse and recurrence. Hence, we modified magnetocaloric Fe3O4 nanoparticles and added them to magnesium calcium phosphate bone cement (MCPC) to fabricate multifunctional magnetic composites for sequential bacterial inhibition, angiogenesis and osteogenesis. Nevertheless, high doses of Mg ions and Fe ions were released from MCPC, which adversely affected osteogenesis. Thus, Fe3O4 was modified using gelatin according to the emulsification crosslinking method, which exhibited a controllable magnetocaloric effect and degradation behavior, and favorable anti-bacterial ability under the action of an alternating magnetic field (AMF). In the early stage, the residual MgO created a local strong alkaline microenvironment by hydrolysis, which inhibited the function and activity of S. aureus and E. coli. At the later stage, the MCPC composites were controllably degraded under the function of gelatin and maintained a long-term local slight alkaline microenvironment that promoted the osteogenic differentiation and mineralization of BMSCs. In vivo subcutaneous implantation experiments further indicated that MCPC composites showed good biocompatibility and facilitated angiogenesis, presenting a promising future in magnetic materials design and infectious bone defect repair.

Nanoscale level gelatin-based scaffolds enhance colony formation of porcine testicular germ cells

The extracellular matrix is important in cell growth, proliferation, and differentiation. Gelatin, a support for adhering cells, is used for coating culture plate surfaces of several primary and stem cells. However, gelatin characteristics on culture plates and its cell interactions are not understood. Here, we aimed to identify the effect of gelatin topography on culture plates on the proliferation and colony formation of porcine spermatogonial germ cells (pSGC). To generate different surface topographies, gelatin powder was dissolved in H₂O at varying melting temperatures (40, 60, 80, and 120 °C) and coated on the surface of the culture plates. At 40 °C, the pores of the gelatin scaffold were regular ellipses 5-6 μm in diameter and 10-30 nm in thickness. However, at 120 °C, irregular pores 20-30 μm in diameter and 10-20 nm in thickness were obtained. Additionally, the number of attached cells and pSGC colonies were significantly more at 40 °C than at 120 °C after a week of culture. Interestingly, the feeder cells did not settle properly at 120 °C but detached easily from the culture dishes. PSGC colonies were 100 μm in diameter at 40 °C, with small and detached colonies observed at 120 °C. Thus, optimal topography of gelatin was obtained at 40 °C, which was sufficient for the proliferation of feeder cells and the formation of pSGC colonies. Thus, gelatin scaffold conditions at 40 °C and 60 °C were optimal for the derivation and culture of pSGC, and gelatin surface morphology is important for the maintenance of supportive feeder cells for pSGC proliferation and colony formation.

β-tricalcium phosphate/gelatin composite scaffolds incorporated with gentamycin-loaded chitosan microspheres for infected bone defect treatment

The repair of infected bone defects remains a clinical challenge. Staphylococcus aureus is a common pathogenic micro-organism associated with such infections. Gentamycin (GM) is a broad spectrum antibiotic that can kill S. aureus in a dose-dependent manner. However, the systemic administration of antibiotics may lead to drug resistance and gut dysbiosis. In this work, we constructed β-tricalcium phosphate/gelatin composite scaffolds incorporated with gentamycin-loaded chitosan microspheres (CMs(GM)-β-TCP/gelatin composite scaffolds), which helped optimize the local GM release in the infected defect areas and enhance bone regeneration. The cumulative release curves showed that both microspheres and composite scaffolds reached a sustained slow-release phase after the initial rapid release, and the latter further stabilized the initial drug release rate. The release curve of CMs(GM)-β-TCP/gelatin composite scaffolds reached a plateau after 24 h, and the cumulative release reached 41.86% during this period. Moreover, the combination of β-TCP and gelatin mimicked bone composition and were able to provide the requisite mechanical strength (0.82 ± 0.05 MPa) during the first phase of bone generation. The inner structure of the scaffold was arranged in the shape of interconnected pores, and presented a porosity level of 16%. The apertures were uniform in size, which was beneficial for cell proliferation and material transportation. Macroscopic observation and histological analysis showed that CMs(GM)-β-TCP/gelatin composite scaffolds fused with bone tissues, and new tissues were formed in defect areas without any infection. This new composite scaffold may be a promising repair material for treating infected bone defects.

Enhancing Stem Cell-Based Therapeutic Potential by Combining Various Bioengineering Technologies

Stem cell-based therapeutics have gained tremendous attention in recent years due to their wide range of applications in various degenerative diseases, injuries, and other health-related conditions. Therapeutically effective bone marrow stem cells, cord blood- or adipose tissue-derived mesenchymal stem cells (MSCs), embryonic stem cells (ESCs), and more recently, induced pluripotent stem cells (iPSCs) have been widely reported in many preclinical and clinical studies with some promising results. However, these stem cell-only transplantation strategies are hindered by the harsh microenvironment, limited cell viability, and poor retention of transplanted cells at the sites of injury. In fact, a number of studies have reported that less than 5% of the transplanted cells are retained at the site of injury on the first day after transplantation, suggesting extremely low (<1%) viability of transplanted cells. In this context, 3D porous or fibrous national polymers (collagen, fibrin, hyaluronic acid, and chitosan)-based scaffold with appropriate mechanical features and biocompatibility can be used to overcome various limitations of stem cell-only transplantation by supporting their adhesion, survival, proliferation, and differentiation as well as providing elegant 3-dimensional (3D) tissue microenvironment. Therefore, stem cell-based tissue engineering using natural or synthetic biomimetics provides novel clinical and therapeutic opportunities for a number of degenerative diseases or tissue injury. Here, we summarized recent studies involving various types of stem cell-based tissue-engineering strategies for different degenerative diseases. We also reviewed recent studies for preclinical and clinical use of stem cell-based scaffolds and various optimization strategies.

A Narrative Review of Cell-Based Approaches for Cranial Bone Regeneration

Current cranial repair techniques combine the use of autologous bone grafts and biomaterials. In addition to their association with harvesting morbidity, autografts are often limited by insufficient quantity of bone stock. Biomaterials lead to better outcomes, but their effectiveness is often compromised by the unpredictable lack of integration and structural failure. Bone tissue engineering offers the promising alternative of generating constructs composed of instructive biomaterials including cells or cell-secreted products, which could enhance the outcome of reconstructive treatments. This review focuses on cell-based approaches with potential to regenerate calvarial bone defects, including human studies and preclinical research. Further, we discuss strategies to deliver extracellular matrix, conditioned media and extracellular vesicles derived from cell cultures. Recent advances in 3D printing and bioprinting techniques that appear to be promising for cranial reconstruction are also discussed. Finally, we review cell-based gene therapy approaches, covering both unregulated and regulated gene switches that can create spatiotemporal patterns of transgenic therapeutic molecules. In summary, this review provides an overview of the current developments in cell-based strategies with potential to enhance the surgical armamentarium for regenerating cranial vault defects.

Bioprinting of Stem Cells in Multimaterial Scaffolds and Their Applications in Bone Tissue Engineering

Bioprinting stem cells into three-dimensional (3D) scaffolds has emerged as a new avenue for regenerative medicine, bone tissue engineering, and biosensor manufacturing in recent years. Mesenchymal stem cells, such as adipose-derived and bone-marrow-derived stem cells, are capable of multipotent differentiation in a 3D culture. The use of different printing methods results in varying effects on the bioprinted stem cells with the appearance of no general adverse effects. Specifically, extrusion, inkjet, and laser-assisted bioprinting are three methods that impact stem cell viability, proliferation, and differentiation potential. Each printing method confers advantages and disadvantages that directly influence cellular behavior. Additionally, the acquisition of 3D bioprinters has become more prominent with innovative technology and affordability. With accessible technology, custom 3D bioprinters with capabilities to print high-performance bioinks are used for biosensor fabrication. Such 3D printed biosensors are used to control conductivity and electrical transmission in physiological environments. Once printed, the scaffolds containing the aforementioned stem cells have a significant impact on cellular behavior and differentiation. Natural polymer hydrogels and natural composites can impact osteogenic differentiation with some inducing chondrogenesis. Further studies have shown enhanced osteogenesis using cell-laden scaffolds in vivo. Furthermore, selective use of biomaterials can directly influence cell fate and the quantity of osteogenesis. This review evaluates the impact of extrusion, inkjet, and laser-assisted bioprinting on adipose-derived and bone-marrow-derived stem cells along with the effect of incorporating these stem cells into natural and composite biomaterials.

Bacterial Cellulose as a Potential Bio-Scaffold for Effective Re-Epithelialization Therapy

Currently, there are several therapeutic approaches available for wound injury management. However, a better understanding of the underlying mechanisms of how biomaterials affect cell behavior is needed to develop potential repair strategies. Bacterial cellulose (BC) is a bacteria-produced biopolymer with several advantageous qualities for skin tissue engineering. The aim here was to investigate BC-based scaffold on epithelial regeneration and wound healing by examining its effects on the expression of scavenger receptor-A (SR-A) and underlying macrophage behavior. Full-thickness skin wounds were generated on Sprague-Dawley rats and the healing of these wounds, with and without BC scaffolds, was examined over 14 days using Masson’s trichome staining. BC scaffolds displayed excellent in vitro biocompatibility, maintained the stemness function of cells and promoted keratinocyte differentiation of cells, which are vital in maintaining and restoring the injured epidermis. BC scaffolds also exhibited positive in vivo effects on the wound microenvironment, including improved skin extracellular matrix deposition and controlled excessive inflammation by reduction of SR-A expression. Furthermore, BC scaffold significantly enhanced epithelialization by stimulating the balance of M1/M2 macrophage re-programming for beneficial tissue repair relative to that of collagen material. These findings suggest that BC-based materials are promising products for skin injury repair.