Biomaterials to enhance stem cell transplantation

Injectable Endoplasmin-Loaded Lipid Nanoparticles-Hydrogel Composite for Cartilage Regeneration

BACKGROUND

Endoplasmin (ENPL), a heat shock protein 90 family member, promotes chondrogenic differentiation of stem cells by inhibiting ERK1/2 phosphorylation and inducing endoplasmic reticulum stress. However, its large size limits cellular uptake and therapeutic potential. To overcome this challenge, a cationic lipid nanoparticle (C_LNP) system was designed to deliver ENPL intracellularly, enhancing its effects on human tonsil-derived mesenchymal stem cells (hTMSCs).

METHODS

ENPL-loaded cationic lipid nanoparticles (ENPL_C_LNP) were synthesized to facilitate intracellular ENPL delivery. The delivery efficiency and cytotoxicity were assessed in vitro using hTMSCs. Additionally, ENPL_C_LNPs were incorporated into a hyaluronic acid and chondroitin sulfate-based injectable hydrogel and tested for chondrogenic differentiation potential in a mouse subcutaneous model.

RESULTS

ENPL_C_LNP achieved over 80% intracellular protein delivery efficiency with no cytotoxic effects. Co-cultured hTMSCs exhibited increased glycosaminoglycans (GAGs) and collagen expression over 21 days. In vivo, the hydrogel-embedded ENPL_C_LNP system enabled stable cartilage differentiation, evidenced by abundant cartilage-specific lacuna structures in regenerated tissue.

CONCLUSION

Combining ENPL_C_LNP with an injectable hydrogel scaffold supports chondrogenic differentiation and cartilage regeneration, offering a promising strategy for cartilage tissue engineering.

Changing genes, cells and networks to reprogram the brain after stroke

Important advances have been made in reperfusion therapies for acute ischemic stroke. However, a majority of patients are either ineligible for or do not respond to treatments and continue to have considerable functional deficits. Stroke results in a pathological disruption of the neurovascular unit (NVU) that involves blood-brain barrier leakage, glial activation, neuronal damage and chronic inflammation, all of which create a microenvironment that hinders recovery. Therefore, finding ways to promote central nervous system recovery remains the holy grail of stroke research. Here we propose a conceptual framework to synthesize recent progress in the field, which is currently dispersed and disconnected in the literature. We suggest that stroke recovery requires an integrated reprogramming process throughout the brain that occurs at multiple levels, including changes in gene expression, endogenous cellular transdifferentiation within the NVU, and reorganization of larger-scale neural and social networks.

Mitochondrial transfer in endothelial cells and vascular health

Mitochondria play a vital role in cellular energy metabolism and vascular health, with their function directly influencing endothelial cell (EC) bioenergetics and integrity. Mitochondrial transfer has emerged as a key mechanism of intercellular communication, impacting angiogenesis, tissue repair, and cellular homeostasis. This review highlights recent findings on mitochondrial transfer, including natural mechanisms - such as tunneling nanotubes (TNTs) and extracellular vesicles (EVs) - and artificial approaches like mitochondrial transplantation. These processes enhance EC function and support vascularization under pathological conditions, including ischemia. While early clinical trials demonstrate therapeutic potential, challenges such as mitochondrial instability and scaling host-derived mitochondria persist. Continued research is essential to optimize mitochondrial transfer and advance its application as a therapeutic strategy for restoring vascular health.

Injectable crosslinked HA hydrogel: a promising carrier for cell transplantation to treat stable vitiligo

Stable vitiligo significantly impacts patients' quality of life and presents a considerable challenge to healthcare providers. In recent years, cell therapy has emerged as a promising treatment for stable vitiligo, which is demonstrated encouraging results. Among current cell-based therapies, autologous epidermal cell transplantation is regarded as a safe and cost-effective strategy. However, the therapeutic outcome critically depends on the retention and viability of the transplanted cells at the target site. Therefore, there is an urgent need to develop novel strategies to improve cell retention and maintain cell viability for improving therapeutic efficacy. In this work, a novel cell extraction method was first developed with deal with 2 h at 37°C to obtain epidermal cells while maintaining high cell viability. Subsequently, the crosslinked hyaluronic acid (HA) by BDDE was utilized as 3D scaffold for cell delivery to treat stable vitiligo. By combining the new extraction method with the HA-based hydrogel scaffold, we achieved prolonged cell retention without compromising cell viability. This approach provides a promising, time-saving strategy for treating stable vitiligo using autologous epidermal cells.

Assembled granular hydrogels loaded with growth factors for enhanced mesenchymal stem cell therapy in abdominal wall defect repair

Abdominal wall defects caused by trauma, congenital rupture, and intra-abdominal infection remain challenging due to the large wound area and complex complications. Herein, an assembled mesenchymal stem cell (MSCs)-laden granular hydrogel (termed assembled GSD@FPs), loaded with basic fibroblast growth factor (bFGF) and platelet-derived growth factor (PDGF), is developed. This hydrogel is constructed through dynamic covalent cross-linking (via borate ester bonds) among dopamine-grafted gelatin methacrylamide (GelMA-DA), phenylborate-modified hyaluronic acid (HA-PBA), and epigallocatechin-3-gallate (EGCG), serving as multifunctional bulk building blocks for cell delivery and abdominal wall repair. The designed assembled granular hydrogels possess good rheological properties, self-healing, injectability, and tissue-adhesion properties. Detailed in vitro cell experiments are conducted, revealing that the GSD@FPs granular hydrogels can effectively promote cell proliferation, cell migration and angiogenesis. Furthermore, in abdominal wall defects, assembled GSD@FPs significantly accelerates the tissue healing process by simultaneously inhibiting the inflammatory response, promoting collagen deposition, and promoting cell proliferation and angiogenesis. Importantly, the assembled GSD@FPs granular hydrogels can also provide mechanical support and increase the thickness of regenerated tissue (1727.8 ± 169.6 μm for the control group, 3204.2 ± 278.5 μm for the assembled GSD@FPs group at 14 d). Eventually, the GSD granular hydrogels biodegraded, facilitating tissue remodeling and generating new muscle tissues. Therefore, this study provides a promising strategy with great potential for application in abdominal wall repair.

Niche-inspired collagen infused melt electrowritten scaffolds for craniofacial bone regeneration

Advances in tissue engineering are focused on devising improved therapeutics to reconstruct craniofacial bones. In cell-based strategies, biomaterials with specific physicochemical properties can mimic natural environments, supporting stem cell renewal, survivability, and cell fate. This study highlights the engineering of a 3D-printed (Melt Electrowritten, MEW) fluorinated‑calcium phosphate (F/CaP)-coated polymeric scaffold infused with collagen (COL) that boosts the performance of transplanted alveolar bone-derived mesenchymal stem cells (aBMSCs). Electron microscopy revealed micron-sized (2.7 μm) polymeric fibers forming a porous (500 μm fiber strand spacing) composite scaffold with a uniform F/CaP coating homogeneously infiltrated with collagen. In vitro, our findings underscored the cytocompatibility of the collagen-infused F/CaP-coated composite scaffold, fostering a suitable environment for aBMSCs proliferation and differentiation. Cells within the F/CaP-coated constructs exhibited upregulated osteogenic gene activity, and the addition of collagen augmented the expression of critical bone-forming genes (i.e., Runx2 and OCN). After in vivo implantation, the scaffolds integrated well with the surrounding host tissue, supporting extensive blood vessel infiltration. Notably, the collagen-infused F/CaP-coated composite scaffolds showed an increased CD31-positive vessel growth compared to the non-coated counterparts. At 8 weeks, aBMSCs-laden F/CaP-Coated+COL composite scaffolds exhibited robust bone formation, creating connecting bony bridges in calvarial defects. Importantly, F/CaP-Coated+COL composite scaffolds displayed pronounced OCN expression, indicating enhanced osteogenic potential. Thus, the engineered F/CaP-coated polymeric scaffold laden with aBMSCs and infused with collagen has proven effective in supporting cell growth, vascularization, and rapid bone regeneration, suggesting potential for future clinical use.

Animal models for the evaluation of retinal stem cell therapies

Retinal degeneration (RD) diseases leading to severe vision loss can affect photoreceptors (PRs) that are responsible for phototransduction, or retinal pigmented epithelium (RPE) providing support for PRs. Human pluripotent stem cell (hPSC)-based therapies are a potential approach for restoration of retinal structure in patients with currently incurable RD diseases. Currently, there are two targeted hPSC therapeutics: PR rescue and PR replacement. PR rescue involves the transplantation of RPE or other neural progenitors into the subretinal space to slow down or prevent further RD. RPE transplantation plays a critical role in preserving photoreceptors by providing trophic support and maintaining retinal integrity, particularly in diseases like age-related macular degeneration (AMD). Advances in RPE transplantation methods, such as polarized monolayer cultures and scaffold-based approaches, have shown promise in enhancing graft survival and integration. However, limitations include inconsistent integration, variable neurotrophic factor secretion, and immune rejection risks in non-autologous transplants. In PR replacement, stem cell-derived photoreceptor-like cells or photoreceptor progenitors (PRP) obtained are transplanted into the eye. While PRPs are commonly obtained from retinal organoids (ROs), alternative sources, such as early differentiation stages or direct differentiation protocols, are also utilized to enhance the efficiency and scalability of PRP generation. Challenges include achieving proper integration, forming outer segments, rosette formation, and avoiding immune rejection or tumorigenicity. Various animal models that simulate human RD diseases are being used for establishing surgical feasibility, graft survival and visual functional recovery but fail to replicate clinical immune challenges. Rodent models lack macula-like structures and have limited reliability in detecting subtle functional changes, while larger animal models pose ethical, logistical, and financial challenges. Immunocompromised models have been developed for minimizing xenograft issues. Visual functional testing for efficacy includes optokinetic testing (OKN), electroretinography (ERG), and electrophysiological recordings from the retina and brain. These tests often fail to capture the complexity of human visual recovery, highlighting the need for advanced models and improved functional testing techniques. This review aims to aggregate current knowledge about approaches to stem cell transplantation, requirements of animal models chosen for validating vision benefits of transplantation studies, advantages of using specific disease models and their limitations. While promising strides have been made, addressing these limitations remains essential for translating stem cell-based therapies into clinical success.

Self-healable and pH-responsive spermidine/ferrous ion complexed hydrogel Co-loaded with CA inhibitor and glucose oxidase for combined cancer immunotherapy through triple ferroptosis mechanism

Tumor microenvironment governs various therapeutic tolerability of cancer such as ferroptosis and immunotherapy through rewiring tumor metabolic reprogramming like Warburg metabolism. Highly expressed carbonic anhydrases (CA) in tumor that maintaining the delicate metabolic homeostasis is thus the most potential target to be modulated to resolve the therapeutic tolerability. Hence, in this article, a self-healable and pH-responsive spermidine/ferrous ion hydrogel loaded with CA inhibitor (acetazolamide, ACZ) and glucose oxidase (ACZ/GOx@SPM-HA Gel) was fabricated through the Schiff-base reaction between spermidine-dextran and oxidized hyaluronic acid, along with ferrous coordination. Investigation on cancer cell lines (MOC-1) demonstrated ACZ/GOx@SPM-HA Gel may induce cellular oxidative stress and mitochondrial dysfunction through disrupting the cellular homeostasis. Moreover, with the facilitation of autophagy induced by spermidine, ACZ/GOx@SPM-HA Gel may trigger a positive feedback loop to maximally amplify cellular ferroptosis and promote DAMPs release. The anti-tumor evaluation on xenograft mice models furtherly proved the local injection of such hydrogel formulation could efficiently inhibit the tumor growth and distinctively promote the immunogenicity of tumor bed to provide a more favorable environment for immunotherapy. Overall, ACZ/GOx@SPM-HA Gel, with such feasible physiochemical properties and great biocompatibility, holds great potential in treating solid tumors with acidosis-mediated immunotherapy tolerance.

Müller Glial-Derived Small Extracellular Vesicles Mitigate RGC Degeneration by Suppressing Microglial Activation via Cx3cl1-Cx3cr1 Signaling

Retinal ganglion cell (RGC) degeneration leads to irreversible blindness. Müller glia (MG) play pivotal roles in retinal homeostasis and disease through paracrine signaling. Small extracellular vesicles (sEVs) are bioactive nanomaterials derived from all types of live cells and are recognized as a potential strategy for neuroprotective therapy. The aim of this study is to investigate the potential roles of MG-derived sEVs (MG-sEVs) in a mouse model of optic nerve injury (ONC). It is found that MG-sEVs treatment effectively mitigates RGC degeneration and suppresses microglial activation, thereby improves visual function in ONC mice. Retinal transcriptomic analysis reveals a strong correlation between C-x3-c motif chemokine ligand 1 (Cx3cl1)-mediated glial activation and inflammation. Subsequently, it is confirmed that the expression levels of Cx3cl1 and proinflammatory cytokines are significantly decreased in retinas treated with MG-sEVs. The components analysis of MG-sEVs cargo identifies that miR-125b-5p and miR-16-5p target Cx3cl1 gene to regulate its expression. It is also observed that Cx3cl1 colocalizes on the microglia of transgenic C-x3-c motif chemokine receptor 1 (Cx3Cr1)-GFP mice. In conclusion, MG-sEVs mitigate RGC degeneration by suppressing microglial activation via Cx3cl1-Cx3cr1 signaling. This research provides additional opportunities for the treatment of RGC degeneration.

Alginate gels: Chemistry, gelation mechanisms, and therapeutic applications with a focus on GERD treatment

Alginate, a natural polysaccharide derived primarily from marine algae, has become popular in biomedical research due to its versatile gelation properties and biocompatibility. This review explores the chemistry, gelation mechanisms, and therapeutic applications of alginate gels, with a particular focus on their role in gastroesophageal reflux disease (GERD) management. Alginate's structure, comprised of guluronic and mannuronic acid blocks, allows for gel formation by ionic cross-linking with divalent cations like calcium ions, generating a stable "egg-box" structure. The effects of pH, temperature, and ion concentration on gelation are explored, as well as other gel forms such as in situ and heat-sensitive gels. Alginate is widely used in the medical and pharmaceutical areas to promote tissue engineering through cell encapsulation and scaffolding, as well as in drug delivery systems for controlled and targeted release. In GERD therapy, alginate produces a gel raft that inhibits acid reflux, providing an effective alternative to proton pump inhibitors. Alginate-based products have demonstrated clinical success, strengthening alginate's medicinal promise. The review also discusses alginate-related issues, such as source variability and stability, as well as innovative modifications to improve treatment effects. These improvements establish alginate as a potential material for customized medication and tailored delivery systems.

Bioinstructive scaffolds enhance stem cell engraftment for functional tissue regeneration

Stem cell therapy is a promising approach for tissue regeneration after traumatic injury, yet current applications are limited by inadequate control over the fate of stem cells after transplantation. Here we introduce a bioconstruct engineered for the staged release of growth factors, tailored to direct different phases of muscle regeneration. The bioconstruct is composed of a decellularized extracellular matrix containing polymeric nanocapsules sequentially releasing basic fibroblast growth factor and insulin-like growth factor 1, which promote the proliferation and differentiation of muscle stem cells, respectively. When applied to a volumetric muscle loss defect in an animal model, the bioconstruct enhances myofibre formation, angiogenesis, innervation and functional restoration. Further, it promotes functional muscle formation with human or aged murine muscle stem cells, highlighting the translational potential of this bioconstruct. Overall, these results highlight the potential of bioconstructs with orchestrated growth factor release for stem cell therapies in traumatic injury.

Development of regenerative therapies targeting fibrotic endometrium in intrauterine adhesion or thin endometrium to restore uterine function

Intrauterine adhesions (IUA) and thin endometrium (TE) represent significant challenges in human reproduction. The condition arises frequently from damage to the endometrial basal layer, leading to fibrous tissue replacing the functional endometrium and impairing the uterus's ability to accept embryo implantation. Conventional treatments, mainly including hysteroscopic adhesiolysis and estrogen therapies, have shown limited success, particularly in severe cases. Regenerative medicine, with its focus on stem cell-based therapies and biomaterials, offers a promising avenue for restoring endometrial function and structure. This review synthesizes the current landscape of endometrial regeneration, focusing on the therapeutic potential of stem cells, the supportive role of biomaterials, and the importance of understanding molecular mechanisms to develop effective strategies for reconstruction of endometrial functional and fertility restoration.

Tβ4-exosome-loaded hemostatic and antibacterial hydrogel to improve vascular regeneration and modulate macrophage polarization for diabetic wound treatment

Diabetic wounds often exhibit delayed healing due to compromised vascular function and intensified inflammation. In this study, we overexpressed Thymosin β4 (Tβ4) in Adipose-Derived Stem Cells (ADSCs) to produce Exosomes (Exos) rich in Tβ4. We then utilized a dual photopolymerizable hydrogel composed of Hyaluronic Acid Methacryloyl (HAMA) and Poly-L-lysine Methacryloyl (PLMA) for the sustained release of Tβ4-Exos on diabetic wounds. The results showed that Tβ4-Exos could stimulate angiogenesis and collagen synthesis, and mitigate inflammation in diabetic wounds by promoting the polarization of M1-type macrophages and inhibiting that of M2-type macrophages. Furthermore, Tβ4-Exos was found to activate the PI3K/AKT/mTOR/HIF-1a signaling pathway, thereby enhancing vascular proliferation. In summary, the sustained release of Tβ4-Exos in HAMA-PLMA (HP) hydrogel and the management of inflammation through the upregulation of the HIF-1a pathway and modulation of macrophage polarization in vascular proliferation significantly accelerated the healing process of diabetic wounds.

Innovative approaches to boost mesenchymal stem cells efficacy in myocardial infarction therapy

Stem cell-based therapy has emerged as a promising approach for heart repair, potentially regenerating damaged heart tissue and improving outcomes for patients with heart disease. However, the efficacy of stem cell-based therapies remains limited by several challenges, including poor cell survival, low retention rates, poor integration, and limited functional outcomes. This article reviews current enhancement strategies to optimize mesenchymal stem cell therapy for cardiac repair. Key approaches include optimizing cell delivery methods, enhancing cell engraftment, promoting cell functions through genetic and molecular modifications, enhancing the paracrine effects of stem cells, and leveraging biomaterials and tissue engineering techniques. By focusing on these enhancement techniques, the paper highlights innovative approaches that can potentially transform stem cell therapy into a more viable and effective treatment option for cardiac repair. The ongoing research and technological advancements continue to push the boundaries, hoping to make stem cell therapy a mainstream treatment for heart disease.

Injectable hyaluronic acid-based microcapsules loaded with human endometrial stem cells improves cardiac function after myocardial infarction

Therapeutic efficacy of human endometrial stem cells (hEnSCs) encapsulated in hyaluronic acid (HA)-based microcapsules for cardiac regeneration in a rat model of MI is investigated. Cell-enclosed microcapsules were made by loading hEnSCs within hydrogel membrane produced from modified HA possessing phenolic hydroxyl moieties (HA-Ph). The hEnSC-loaded HA-Ph microcapsules (≈150 μm) injected intramyocardially into the peri-infarct area post-MI. The encapsulated cells showed mechanical stability and >87 % cell viability with cellular aggregation in size of about 100 μm until 7 days of culture. Transthoracic echocardiography evaluation indicated a significant increase in ejection fraction in encapsulated cells, compared to the other groups. Histological investigation of fibrosis and scar area by Masson trichrome and hematoxylin and eosin (H&E) staining illustrated less fibrosis and scarring area in the encapsulated cell group compared with the other groups. Furthermore, the cell-laden microcapsules significantly enhance expression intensities of actin and troponin as well as vascular endothelial-specific marker, all of which promote cardiac functions and contribute to a better therapeutic effect than the free-cell injection group in a rat model of MI. Our findings demonstrated that both hEnSCs and specifically hEnSC-loaded HA-based hydrogel vehicle can provide a promising novel therapy for functional restoration in MI instances.

3D bioprinted dynamic bioactive living construct enhances mechanotransduction-assisted rapid neural network self-organization for spinal cord injury repair

Biomimetic neural substitutes, constructed through the bottom-up assembly of cell-matrix modulus via 3D bioprinting, hold great promise for neural regeneration. However, achieving precise control over the fate of neural stem cells (NSCs) to ensure biological functionality remains challenging. Cell behaviors are closely linked to cellular dynamics and cell-matrix mechanotransduction within a 3D microenvironment. To address this, a dynamic bioactive bioink is designed to provide adaptable biomechanics and instructive biochemical cues, specifically tailored for the fate commitment of NSCs, through incorporating reversible Schiff-base bonds and bioactive motifs, N-cadherin-mimicking and BDNF-mimicking peptides. We demonstrate that the dynamic properties of 3D bioprinted living fibers alleviate the mechanical confinement on NSCs and significantly enhance their mechanosensing, spreading, migration, and matrix remodeling within the 3D matrix. Additionally, the inclusion of N-cadherin-mimicking and BDNF-mimicking peptides further enhances cells' ability to sense and respond to mechanical and neurotrophic cues provided by the surrounding matrix, which accelerates the self-organization of a functional neural network within the 3D bioprinted construct, leading to significant motor and sensory function recovery in a rat complete spinal cord injury model. This work underscores the critical role of precisely designing cell-instructive bioinks for the advanced functionality of 3D bioprinted living constructs in neural regeneration.

Mesenchymal Stem Cells Loaded in Injectable Alginate Hydrogels Promote Liver Growth and Attenuate Liver Fibrosis in Cirrhotic Rats

Cirrhosis, a marker of severe liver diseases, limits future liver remnant (FLR) growth, preventing many cancer patients from undergoing surgery. While portal vein blockade (PVB) techniques are used to stimulate liver regeneration, 20-30% of patients still fail to achieve the required growth. Although mesenchymal stem cell (MSC) therapy improves PVB, its efficacy is limited by poor cell retention. To address this, we utilized alginate hydrogels to deliver MSCs and improve their retention. MSCs were loaded in the hydrogel and injected intraportally in cirrhotic rats. Liver volume, weights, enzyme levels, and histology were monitored. Results showed that the hydrogel maintained 89.0 ± 3.0% cell viability and gradually released MSCs for over two weeks. Furthermore, the rats injected with the MSC-loaded hydrogel demonstrated higher liver volumes (FLR ratio of 0.57 ± 0.32) and weights (FLR ratio of 0.84 ± 0.05). The treated rats exhibited more improved liver enzymes (AST: 72.75 ± 14.17 U/L, ALP: 135.67 ± 41.20 U/L, ALT: 46.00 ± 2.94 U/L) and decreased fibrotic areas in the liver (4.52 ± 0.22%) compared to the control group. Histology revealed increased retention when MSCs were delivered with the hydrogel (37.30 ± 16.10 MSCs/mm2) compared to cells alone (21.70 ± 22.10 MSCs/mm2). Overall, the MSC-loaded hydrogels enhanced the growth and reduced the fibrosis of the liver by promoting cell retention and efficacy in cirrhotic rats. This approach holds significant potential for improving outcomes among cancer patients, offering a promising therapeutic strategy for liver regeneration and treatment of liver diseases.

Bioinstructive 3D-Printed Magnesium-Baghdadite Bioceramic Scaffolds for Bone Tissue Engineering

Current synthetic bioceramic scaffolds often lack bioinstructive ability for effective bone regeneration. We have selected magnesium-doped baghdadite (Mg-BAG) scaffolds, known for their promising osteoinductive and mechanical properties, as the base material and fabricated them using a liquid crystal display 3D printing technique. Building on this foundation, we have advanced the application of ion-assisted plasma polymerization (IAPP) technology, adapted for 3D structures, to develop homogeneous bioinstructive interfaces on these scaffolds for enhanced osteoinductive properties. The IAPP coatings formed under energetic ion bombardment maintained a strong attachment to the Mg-BAG scaffolds after 1 month of incubation at 37 °C in cell culture media. We provided evidence that such robustness of the interfaces is regulated by the coating's growth mechanism on a nanoscale, transitioning from initial island formation to a stable, smooth structure. The coatings enhanced the release of silicon ions from the scaffolds and significantly slowed the release of bone morphogenetic protein 2 (BMP2) over a period of 45 days. In the presence of lower soluble BMP2 concentrations, the biofunctionalized scaffolds demonstrated superior biocompatibility and osteoinductivity compared to those with physisorbed BMP2, as evidenced by sustained cell proliferation and elevated levels of osteogenic gene expression observed in human osteoblast-like cells (HOBs). This research highlights a key evolution of IAPP from traditional 2D substrates to more complex 3D structures and the excellent potential of IAPP bioceramic scaffolds as a next generation of cell-free constructs for bone regeneration applications and beyond.

Implantation of engineered adipocytes suppresses tumor progression in cancer models

Tumors exhibit an increased ability to obtain and metabolize nutrients. Here, we implant engineered adipocytes that outcompete tumors for nutrients and show that they can substantially reduce cancer progression, a technology termed adipose manipulation transplantation (AMT). Adipocytes engineered to use increased amounts of glucose and fatty acids by upregulating UCP1 were placed alongside cancer cells or xenografts, leading to significant cancer suppression. Transplanting modulated adipose organoids in pancreatic or breast cancer genetic mouse models suppressed their growth and decreased angiogenesis and hypoxia. Co-culturing patient-derived engineered adipocytes with tumor organoids from dissected human breast cancers significantly suppressed cancer progression and proliferation. In addition, cancer growth was impaired by inducing engineered adipose organoids to outcompete tumors using tetracycline or placing them in an integrated cell-scaffold delivery platform and implanting them next to the tumor. Finally, we show that upregulating UPP1 in adipose organoids can outcompete a uridine-dependent pancreatic ductal adenocarcinoma for uridine and suppress its growth, demonstrating the potential customization of AMT.

Glial Cell Reprogramming in Ischemic Stroke: A Review of Recent Advancements and Translational Challenges

Ischemic stroke, the second leading cause of death worldwide and the leading cause of long-term disabilities, presents a significant global health challenge, particularly in aging populations where the risk and severity of cerebrovascular events are significantly increased. The aftermath of stroke involves neuronal loss in the infarct core and reactive astrocyte proliferation, disrupting the neurovascular unit, especially in aged brains. Restoring the balance between neurons and non-neuronal cells within the perilesional area is crucial for post-stroke recovery. The aged post-stroke brain mounts a fulminant proliferative astroglial response, leading to gliotic scarring that prevents neural regeneration. While countless therapeutic techniques have been attempted for decades with limited success, alternative strategies aim to transform inhibitory gliotic tissue into an environment conducive to neuronal regeneration and axonal growth through genetic conversion of astrocytes into neurons. This concept gained momentum following discoveries that in vivo direct lineage reprogramming in the adult mammalian brain is a feasible strategy for reprogramming non-neuronal cells into neurons, circumventing the need for cell transplantation. Recent advancements in glial cell reprogramming, including transcription factor-based methods with factors like NeuroD1, Ascl1, and Neurogenin2, as well as small molecule-induced reprogramming and chemical induction, show promise in converting glial cells into functional neurons. These approaches leverage the brain's intrinsic plasticity for neuronal replacement and circuit restoration. However, applying these genetic conversion therapies in the aged, post-stroke brain faces significant challenges, such as the hostile inflammatory environment and compromised regenerative capacity. There is a critical need for safe and efficient delivery methods, including viral and non-viral vectors, to ensure targeted and sustained expression of reprogramming factors. Moreover, addressing the translational gap between preclinical successes and clinical applications is essential, emphasizing the necessity for robust stroke models that replicate human pathophysiology. Ethical considerations and biosafety concerns are critically evaluated, particularly regarding the long-term effects and potential risks of genetic reprogramming. By integrating recent research findings, this comprehensive review provides an in-depth understanding of the current landscape and future prospects of genetic conversion therapy for ischemic stroke rehabilitation, highlighting the potential to enhance personalized stroke management and regenerative strategies through innovative approaches.

Innovative approaches to tissue engineering: Utilizing decellularized extracellular matrix hydrogels for mesenchymal stem cell transport

In recent years, the realm of tissue regeneration experienced significant advancements, leading to the development of innovative therapeutic agents. The systemic delivery of mesenchymal stem cells (MSCs) emerged as a promising strategy for promoting tissue regeneration. However, this approach is hindered by hurdles such as poor cell survival, limited cell propagation, and inadequate cell integration. Decellularized extracellular matrix (dECM) hydrogel serves as an innovative carrier that protects MSCs from the detrimental effects of the hostile microenvironment, facilitates their localization and retention at the injection site, and preserves their viability. Regarding its low immunogenicity, low cytotoxicity, high biocompatibility, and its ability to mimic natural extracellular matrix (ECM), this natural hydrogel offers a new avenue for systemic delivery of MSCs. This review digs into the properties of dECM hydrogels (dECMHs), the methods employed for decellularization and the utilization of dECMH as carriers for various types of MSCs for tissue regeneration purposes. This review also sheds light on the benefits of hybrid hydrogels composed of dECMH and other components such as proteins and polysaccharides. By addressing the limitations of conventional hydrogels and enhancing efficacy of cell therapy, dECMH opens new pathways for the future of tissue regeneration.

Material-driven immunomodulation and ECM remodeling reverse pulmonary fibrosis by local delivery of stem cell-laden microcapsules

Recent progress in stem cell therapy has demonstrated the therapeutic potential of intravenous stem cell infusions for treating the life-threatening lung disease of pulmonary fibrosis (PF). However, it is confronted with limitations, such as a lack of control over cellular function and rapid clearance by the host after implantation. In this study, we developed an innovative PF therapy through tracheal administration of microfluidic-templated stem cell-laden microcapsules, which effectively reversed the progression of inflammation and fibrotic injury. Our findings highlight that hydrogel microencapsulation can enhance the persistence of donor mesenchymal stem cells (MSCs) in the host while driving MSCs to substantially augment their therapeutic functions, including immunoregulation and matrix metalloproteinase (MMP)-mediated extracellular matrix (ECM) remodeling. We revealed that microencapsulation activates the MAPK signaling pathway in MSCs to increase MMP expression, thereby degrading overexpressed collagen accumulated in fibrotic lungs. Our research demonstrates the potential of hydrogel microcapsules to enhance the therapeutic efficacy of MSCs through cell-material interactions, presenting a promising yet straightforward strategy for designing advanced stem cell therapies for fibrotic diseases.

Enhanced secretion of growth factors from ADSCs using an enzymatic antioxidant hydrogel in inflammatory environments and its therapeutic effect

A catalytic ROS-scavenging hydrogel (HGel) was developed to enhance the growth factor secretion and the therapeutic efficacy of human adipose-derived stem cells (hADSCs) in inflammatory environments. The HGel is composed of heparin and hyaluronic acid, further functionalized with hemin to endow superoxide dismutase and catalase activities. The functionalization of hemin enables the HGel to effectively scavenge ROS (superoxide and H2O2), thereby protecting encapsulated hADSCs from oxidative stress and maintaining their metabolic activities. As a result, the HGel enhanced growth factor secretion of hADSCs in inflammatory conditions compared to non-functionalized, bare heparin/hyaluronic acid hydrogel (Gel). The therapeutic efficacy of the hADSC-encapsulated HGel (C/HGel) was evaluated in a diabetic wound model. The C/HGel significantly accelerated wound closure, reduced ROS levels, mitigated inflammation, and promoted angiogenesis compared to the hADSC-encapsulated Gel (C/Gel) as well as the HGel itself. The HGel has the potential to be utilized as an excellent cell carrier for stem cell therapy in various inflammatory diseases. Overall, this study demonstrated a strategy of enhancing growth factor secretion from stem cells using catalytic antioxidant hydrogels for superior regenerative effects in cell therapy.

Exploring the potential of laser-textured metal alloys: Fine-tuning vascular cells responses through in vitro and ex vivo analysis

Medical stents are vital for treating vascular complications and restoring blood flow in millions of patients. Despite its widespread effectiveness, restenosis, driven by the complex interplay of cellular responses, remains a concern. This study investigated the reactions of vascular cells to nano/microscale wrinkle (nano-W and micro-W) patterns created on laser-textured nitinol (NiTi) surfaces by adjusting laser processing parameters, such as spot overlap ratio and line overlap ratio. Evaluation of topographical effects on endothelial and smooth muscle cells (SMCs) revealed diverse morphologies, proliferation rates, and gene expressions. Notably, microscale wrinkle patterns exhibited reduced monocyte adhesion and inflammation-related gene expression, demonstrating their potential applications in mitigating vascular complications after stent insertion. Additionally, an ex vivo metatarsal assay was utilized to bridge the gap between in vitro and in vivo studies, demonstrating enhanced angiogenesis on laser-textured NiTi surfaces. Laser-textured NiTi exhibits a guided formation process, emphasizing their potential to promote swift endothelialization. These findings underscore the efficacy of laser texturing for tailored cellular interactions on metallic surfaces and offer valuable insights into optimizing biocompatibility and controlling cellular responses, which may pave the way for innovative advances in vascular care and contribute to the ongoing improvement of stent insertion.

Gellan gum as a promising transplantation carrier for differentiated progenitor cells in ophthalmic therapies

Stem cell-based therapies for various ocular conditions are increasingly gaining traction in ophthalmic treatments, with hydrogel-based polymers playing a pivotal role. Current stem cell delivery methods face challenges such as limited cell retention, immunological rejection, and uneven dispersion. Hence, there is a critical demand for innovative delivery systems to enhance the viability, localization, and integration of transplanted stem cells while minimizing adverse effects. Central to this advancement is the meticulous selection of appropriate materials. Among the promising options, gellan gum, a versatile polysaccharide, is emerging as a potential carrier for differentiated progenitor cells in regenerative medicine, particularly in ophthalmology. This study explores the utilization of gellan gum hydrogels as carriers, focusing on their biocompatibility, customizable gelation properties, and ability to encapsulate, transplant, and biofunctionalize cells. Through a review of literature, the impact of gellan gum hydrogels on cell viability parameters is investigated, revealing their potential for promoting tissue regeneration and functional recovery in ocular diseases. Furthermore, this study compares gellan gum systems utilizing natural and synthetic polymers, discerning differences in efficacy, biocompatibility, and suitability for diverse applications in regenerative ophthalmology. This review highlights the promising role of gellan gum in ophthalmic therapies, providing valuable insights into future directions and hurdles in this evolving field.

Therapeutic Interventions for Diabetes Mellitus-associated Complications

BACKGROUND

Diabetes Mellitus (DM) is an alarming health concern, affecting approximately 537 million people worldwide. As a leading cause of morbidity and mortality, DM demands a comprehensive understanding of its diverse pathophysiological mechanisms and disease progression.

METHODS

This traditional review has consolidated literature on the pathogenesis of hyperglycemia, its progression into complications, and advances in optimal treatment strategies. The literature in the last two decades has been reviewed using several keywords, including "diabetes," "diabetes-associated complications", "novel therapeutic interventions for diabetes-associated diseases", "phyto-extracts as antidiabetic drugs", etc. in prominent databases, such as PubMed, Scopus, Google Scholar, Web of Science, and ClinicalTrials.gov.

RESULTS

We have discussed macrovascular and microvascular complications, such as atherosclerosis, cardiovascular disease, Peripheral Arterial Disease (PAD), stroke, diabetic nephropathy, retinopathy, and neuropathy, as well as various pharmacological and non-pharmacological interventions that are currently available for the management of DM. We have also focused on the potential of natural products in targeting molecular mechanisms involved in carbohydrate metabolism, insulin production, repair of pancreatic cells, and reduction of oxidative stress, thereby contributing to their antidiabetic activity. Additionally, novel therapeutic approaches, like genetic, stem cell, and immunomodulatory therapies, have been explored. We have also discussed the benefits and limitations of each intervention, emerging research and technologies, and precision medicine interventions.

CONCLUSION

This review has emphasized the need for an improved understanding of these advancements, which is essential to enhance clinicians' ability to identify the most effective therapeutic interventions.

Assessment of the level of apoptosis in differentiated pseudo-neuronal cells derived from neural stem cells under the influence of various inducers

Development and maintenance of the nervous system are governed by a scheduled cell death mechanism known as apoptosis. Very much how neurons survive and function depends on the degree of death in differentiating pseudo-neuronal cells produced from neural stem cells. Different inducers can affect the degree of death in these cells: hormones, medicines, growth factors, and others. Developing inventive therapies for neurodegenerative illnesses depends on a knowledge of how these inducers impact mortality in differentiated pseudo-neuronal cells. Using flow cytometry, Western blotting, and fluorescence microscopy among other techniques, the degree of death in many pseudo-neuronal cells is evaluated. Flow cytometry generates dead cell counts from measurements of cell size, granularity, and DNA content. Whereas fluorescence microscopy visualizes dead cells using fluorescent dyes or antibodies, Western blotting detects caspases and Bcl-2 family proteins. This review attempts to offer a thorough investigation of present studies on death in differentiated pseudo-neuronal cells produced from neural stem cells under the effect of different inducers. Through investigating how these inducers influence death, the review aims to provide information that might direct the next studies and support treatment plans for neurodegenerative diseases. With an eye toward inducers like retinoic acid, selegiline, cytokines, valproic acid, and small compounds, we examined research to evaluate death rates. The findings offer important new perspectives on the molecular processes guiding death in these cells. There is still a complete lack of understanding of how different factors affect the molecular processes that lead to death, so understanding these processes can contribute to new therapeutic approaches to treat neurodegenerative diseases.

Magnetic soft microrobots for erectile dysfunction therapy

Erectile dysfunction (ED) is a major threat to male fertility and quality of life, and mesenchymal stromal cells (MSCs) are a promising therapeutic option. However, therapeutic outcomes are compromised by low MSC retention and survival rates in corpus cavernosum tissue. Here, we developed an innovative magnetic soft microrobot comprising an ultrasoft hydrogel microsphere embedded with a magnetic nanoparticle chain for MSC delivery. This design also features phenylboronic acid groups for scavenging reactive oxygen species (ROS). With a Young's modulus of less than 1 kPa, the ultrasoft microrobot adapts its shape within narrow blood vessels, ensuring a uniform distribution of MSCs within the corpus cavernosum. Our findings showed that compared with traditional MSC injections, the MSC delivery microrobot (MSC-Rob) significantly enhanced MSC retention and survival. In both rat and beagle ED models, MSC-Rob treatment accelerated the repair of corpus cavernosum tissue and restored erectile function. Single-cell RNA sequencing (scRNA-seq) revealed that MSC-Rob treatment facilitates nerve and blood vessel regeneration in the corpus cavernosum by increasing the presence of regenerative macrophages. Overall, our MSC-Rob not only advances the clinical application of MSCs for ED therapy but also broadens the scope of microrobots for other cell therapies.

Stem cell transplantation therapy for advanced liver damage-associated neurodegenerative disorders

Hepatic encephalopathy and other neurodegenerative disorders have profound implications for extensive liver impairment, calling for new ways of treating the condition. The application of stem cell transplantation to treat these severe disorders is a new and encouraging technique. This review article digs deep into the subject of stem cell transplantation therapy, neurodegenerative disorders associated with advanced liver damage, and liver transplantation. It comprehensively analyses the background, rationale, scope, and objectives of using stem cells to treat such challenging conditions. The topic of discussion includes the subtleties of neurodegenerative disorders, the function of liver transplantation, and the possible advantages and disadvantages associated with it. The relevance of patient selection, intraoperative concerns and post-transplant care is discussed. Further, the article explores how stem cell-based therapies can benefit from nanotechnology, specifically how it can improve stem cell distribution, survival, and integration for better therapeutic results. This review aims to offer a thorough analysis of regenerative medicine's present and future possibilities in dealing with the intricate relationship between neurodegeneration and liver damage. It does this by examining the efficacy, safety, and long-term impacts of stem cell transplantation in treating neurodegenerative disorders associated with advanced liver damage. This will incorporate insights from ongoing clinical trials, the patent landscape, and future directions. The goal is to pave the way for innovative and personalized treatment approaches in this evolving research and clinical practice field. Therefore, these efforts represent a promising frontier in medical research that can alleviate the burden of HE and associated neurological complications combined with liver cirrhosis.

Role of the Pancreatic Islet Microvasculature in Health and Disease

The pancreatic islet vasculature comprises microvascular endothelial cells surrounded by mural cells (pericytes). Both cell types support the islet by providing (1) a conduit for delivery and exchange of nutrients and hormones; (2) paracrine signals and extracellular matrix (ECM) components that support islet development, architecture, and endocrine function; and (3) a barrier against inflammation and immune cell infiltration. In type 2 diabetes, the islet vasculature becomes inflamed, showing loss of endothelial cells, detachment, and/or trans-differentiation of pericytes, vessel dilation, and excessive ECM deposition. While most work to date has focused either on endothelial cells or pericytes in isolation, it is very likely that the interaction between these cell types and disruption of that interaction in diabetes are critically important. In fact, dissociation of pericytes from endothelial cells is an early, key feature of microvascular disease in multiple tissues/disease states. Moreover, in beta-cell replacement therapy, co-transplantation with microvessels versus endothelial cells alone is substantially more effective in improving survival and function of the transplanted cells. Ongoing studies, including characterization of islet vascular cell signatures, will aid in the identification of new therapeutic targets aimed at improving islet function and benefiting people living with all forms of diabetes.

Advances in retinal pigment epithelial cell transplantation for retinal degenerative diseases

Retinal degenerative diseases are a leading cause of vision loss and blindness globally, impacting millions. These diseases result from progressive damage to retinal pigment epithelial (RPE) cells for which no curative or palliative treatments exist. Cell therapy, particularly RPE transplantation, has emerged as a promising strategy for vision restoration. This review provides a comprehensive overview of the recent advancements in clinical trials related to RPE transplantation. We discuss scaffold-free and scaffold-based approaches, including RPE cell suspensions and pre-organized RPE monolayers on biomaterial scaffolds. Key considerations, such as the form and preparation of RPE implants, delivery devices, strategies, and biodegradability of scaffolds, are examined. The article also explores the challenges and opportunities in RPE scaffold development, emphasising the crucial need for functional integration, immunomodulation, and long-term biocompatibility to ensure therapeutic efficacy. We also highlight ongoing efforts to optimise RPE transplantation methods and their potential to address retinal degenerative diseases.

Prussian Blue Nanohybridized Multicellular Spheroids as Composite Engraftment for Antioxidant Bone Regeneration and Photoacoustic Tomography

Regulating the complex microenvironment after tooth extraction to promote alveolar bone regeneration is a pressing challenge for restorative dentistry. In this study, through modulating the mechanical properties of the cellular matrix, we guided various types of cells by self-organizing to form multicellular spheroids (MCSs) and hybridized MCSs with Prussian Blue nanoparticles (PBNPs) in the process. The constructed Prussian Blue nanohybridized multicellular spheroids (PBNPs@MCSs) with empowered antioxidant functions effectively reduced cell apoptosis under peroxidative conditions and exhibited enhanced ability to regulate the microenvironment and promote bone repair both in vitro and in vivo. In addition, the PBNPs@MCSs exhibited enhanced photoacoustic imaging ability to trace low doses of PBNPs. Therefore, the constructed PBNPs@MCSs based on the biomimetic hydrogel can be used as a form of an engraftment building block, with a greater potential for pro-bone repair application in the complex microenvironment of the oral cavity.

An update on stem cell therapy for stroke patients: Where are we now?

With a foundation built upon initial work from the 1980s demonstrating graft viability in cerebral ischemia, stem cell transplantation has shown immense promise in promoting survival, enhancing neuroprotection and inducing neuroregeneration, while mitigating both histological and behavioral deficits that frequently accompany ischemic stroke. These findings have led to a number of clinical trials that have thoroughly supported a strong safety profile for stem cell therapy in patients but have generated variable efficacy. As preclinical evidence continues to expand through the investigation of new cell lines and optimization of stem cell delivery, it remains critical for translational models to adhere to the protocols established through basic scientific research. With the recent shift in approach towards utilization of stem cells as a conjunctive therapy alongside standard thrombolytic treatments, key issues including timing, route of administration, and stem cell type must each be appropriately translated from the laboratory in order to resolve the question of stem cell efficacy for cerebral ischemia that ultimately will enhance therapeutics for stroke patients towards improving quality of life.

Advancements and challenges in stem cell transplantation for regenerative medicine

Stem cell transplantation has emerged as a promising avenue in regenerative medicine, potentially facilitating tissue repair in degenerative diseases and injuries. This review comprehensively examines recent developments and challenges in stem cell transplantation. It explores the identification and isolation of various stem cell types, including embryonic, induced pluripotent, and adult stem cells derived from multiple sources. Additionally, the review highlights the tissue-specific applications of these stem cells, focusing on bone and cartilage regeneration, treatment of neurological disorders, and management of hematological conditions. Future advancements and effective resolution of current challenges will be crucial in fully realizing the potential of stem cell transplantation in regenerative medicine. With responsible and ethical practices, the field can potentially transform disease and injury treatment, ultimately improving the quality of life for countless individuals.

Recent Advances in Nanomaterials for Modulation of Stem Cell Differentiation and Its Therapeutic Applications

Challenges in directed differentiation and survival limit the clinical use of stem cells despite their promising therapeutic potential in regenerative medicine. Nanotechnology has emerged as a powerful tool to address these challenges and enable precise control over stem cell fate. In particular, nanomaterials can mimic an extracellular matrix and provide specific cues to guide stem cell differentiation and proliferation in the field of nanotechnology. For instance, recent studies have demonstrated that nanostructured surfaces and scaffolds can enhance stem cell lineage commitment modulated by intracellular regulation and external stimulation, such as reactive oxygen species (ROS) scavenging, autophagy, or electrical stimulation. Furthermore, nanoframework-based and upconversion nanoparticles can be used to deliver bioactive molecules, growth factors, and genetic materials to facilitate stem cell differentiation and tissue regeneration. The increasing use of nanostructures in stem cell research has led to the development of new therapeutic approaches. Therefore, this review provides an overview of recent advances in nanomaterials for modulating stem cell differentiation, including metal-, carbon-, and peptide-based strategies. In addition, we highlight the potential of these nano-enabled technologies for clinical applications of stem cell therapy by focusing on improving the differentiation efficiency and therapeutics. We believe that this review will inspire researchers to intensify their efforts and deepen their understanding, thereby accelerating the development of stem cell differentiation modulation, therapeutic applications in the pharmaceutical industry, and stem cell therapeutics.

Mining human clinical waste as a rich source of stem cells for neural regeneration

Neural diseases are challenging to treat and are regarded as one of the major causes of disability and morbidity in the world. Stem cells can provide a solution, by offering a mechanism to replace damaged circuitry. However, obtaining sufficient cell sources for neural regeneration remains a significant challenge. In recent years, waste-derived stem(-like) cells (WDS-lCs) extracted from both prenatal and adult clinical waste tissues/products, have gained increasing attention for application in neural tissue repair and remodeling. This often-overlooked pool of cells possesses favorable characteristics; including self-renewal, neural differentiation, secretion of neurogenic factors, cost-effectiveness, and low ethical concerns. Here, we offer a perspective regarding the biological properties, extraction protocols, and preclinical and clinical treatments where prenatal and adult WDS-lCs have been utilized for cell replacement therapy in neural applications, and the challenges involved in optimizing these approaches toward patient led therapies.

Mesenchymal stem cells biological and biotechnological advances: Implications for clinical applications

BACKGROUND

Mesenchymal stem cells (MSCs) are multipotent stem cells that are able to differentiate into multiple lineages including bone, cartilage, muscle and fat. They hold immunomodulatory properties and therapeutic ability to treat multiple diseases, including autoimmune and chronic degenerative diseases. In this article, we reviewed the different biological properties, applications and clinical trials of MSCs. Also, we discussed the basics of manufacturing conditions, quality control, and challenges facing MSCs in the clinical setting.

METHODS

Extensive review of the literature was conducted through the databases PubMed, Google Scholar, and Cochrane. Papers published since 2015 and covering the clinical applications and research of MSC therapy were considered. Furthermore, older papers were considered when referring to pioneering studies in the field.

RESULTS

The most widely studied stem cells in cell therapy and tissue repair are bone marrow-derived mesenchymal stem cells. Adipose tissue-derived stem cells became more common and to a lesser extent other stem cell sources e.g., foreskin derived MSCs. MSCs therapy were also studied in the setting of COVID-19 infections, ischemic strokes, autoimmune diseases, tumor development and graft rejection. Multiple obstacles, still face the standardization and optimization of MSC therapy such as the survival and the immunophenotype and the efficiency of transplanted cells. MSCs used in clinical settings displayed heterogeneity in their function despite their extraction from healthy donors and expression of similar surface markers.

CONCLUSION

Mesenchymal stem cells offer a rising therapeutic promise in various diseases. However, their potential use in clinical applications requires further investigation.

Advances in Nanomedicine and Biomaterials for Endometrial Regeneration: A Comprehensive Review

The endometrium is an extremely important component of the uterus and is crucial for individual health and human reproduction. However, traditional methods still struggle to ideally repair the structure and function of damaged endometrium and restore fertility. Therefore, seeking and developing innovative technologies and materials has the potential to repair and regenerate damaged or diseased endometrium. The emergence and functionalization of various nanomedicine and biomaterials, as well as the proposal and development of regenerative medicine and tissue engineering techniques, have brought great hope for solving these problems. In this review, we will summarize various nanomedicine, biomaterials, and innovative technologies that contribute to endometrial regeneration, including nanoscale exosomes, nanomaterials, stem cell-based materials, naturally sourced biomaterials, chemically synthesized biomaterials, approaches and methods for functionalizing biomaterials, as well as the application of revolutionary new technologies such as organoids, organ-on-chips, artificial intelligence, etc. The diverse design and modification of new biomaterials endow them with new functionalities, such as microstructure or nanostructure, mechanical properties, biological functions, and cellular microenvironment regulation. It will provide new options for the regeneration of endometrium, bring new hope for the reconstruction and recovery of patients' reproductive abilities.

An Autoclavable and Transparent Thermal Cutter for Reliably Sealing Wet Nanofibrous Membranes

Sealing wet porous membranes is a major challenge when fabricating cell encapsulation devices. Herein, we report the development of an Autoclavable Transparent Thermal Cutter (ATTC) for reliably sealing wet nanofibrous membranes. Notably, the ATTC is autoclavable and transparent, thus enabling in situ visualization of the sealing process in a sterile environment and ensuring an appropriate seal. In addition, the ATTC could generate smooth, arbitrary-shaped sealing ends with excellent mechanical properties when sealing PA6, PVDF, and TPU nanofibrous tubes and PP microporous membranes. Importantly, the ATTC could reliably seal wet nanofibrous tubes, which can shoulder a burst pressure up to 313.2 ± 19.3 kPa without bursting at the sealing ends. Furthermore, the ATTC sealing process is highly compatible with the fabrication of cell encapsulation devices, as verified by viability, proliferation, cell escape, and cell function tests. We believe that the ATTC could be used to reliably seal cell encapsulation devices with minimal side effects.

Biomimetic electrospun PVDF/self-assembling peptide piezoelectric scaffolds for neural stem cell transplantation in neural tissue engineering

Piezoelectric materials can provide in situ electrical stimulation without external chemical or physical support, opening new frontiers for future bioelectric therapies. Polyvinylidene fluoride (PVDF) possesses piezoelectricity and biocompatibility, making it an electroactive biomaterial capable of enhancing bioactivity through instantaneous electrical stimulation, which indicates significant potential in tissue engineering. In this study, we developed electroactive and biomimetic scaffolds made of electrospun PVDF and self-assembling peptides (SAPs) to enhance stem cell transplantation for spinal cord injury regeneration. We investigated the morphology and crystalline polymorphs of the electrospun scaffolds. Morphological studies demonstrated the benefit of using mixed sodium dodecyl sulfate (SDS) and SAPs as additives to form thinner, uniform, and defect-free fibers. Regarding electroactive phases, β and γ phases-evidence of electroactivity-were predominant in aligned scaffolds and scaffolds modified with SDS and SAPs. In vitro studies showed that neural stem cells (NSCs) seeded on electrospun PVDF with additives exhibited desirable proliferation and differentiation compared to the gold standard. Furthermore, the orientation of the fibers influenced scaffold topography, resulting in a higher degree of cell orientation in fiber-aligned scaffolds compared to randomly oriented ones.

Accelerating Diverse Cell-Based Therapies Through Scalable Design

Augmenting cells with novel, genetically encoded functions will support therapies that expand beyond natural capacity for immune surveillance and tissue regeneration. However, engineering cells at scale with transgenic cargoes remains a challenge in realizing the potential of cell-based therapies. In this review, we introduce a range of applications for engineering primary cells and stem cells for cell-based therapies. We highlight tools and advances that have launched mammalian cell engineering from bioproduction to precision editing of therapeutically relevant cells. Additionally, we examine how transgenesis methods and genetic cargo designs can be tailored for performance. Altogether, we offer a vision for accelerating the translation of innovative cell-based therapies by harnessing diverse cell types, integrating the expanding array of synthetic biology tools, and building cellular tools through advanced genome writing techniques.

Mesenchymal stem cell based therapies for uveitis: a systematic review of preclinical studies

Cell therapy has shown promising results for treating uveitis in preclinical studies. As the field continues to grow towards clinical translation, it is important to review and critically appraise existing studies. Herein, we analysed and critically appraised all preclinical studies using cell therapy or cell derived extracellular vesicles (EVs) for uveitis, and provided insight into mechanisms regulating ocular inflammation. We used PubMed, Medline, and Embase to search for preclinical studies examining stem cell therapy (e.g., mesenchymal stem cells [MSC]) and secreted EVs. All included studies were assessed for quality using the SYstematic Review Center for Laboratory animal Experimentation (SYRCLE) checklist. Sixteen preclinical studies from 2011 to 2022 were analysed and included in this review of which 75% (n = 12) focused only on cell therapy, 18.7% (n = 3) studies focused on EVs, and 6.3% (n = 1) study focused on both cells and EVs. MSCs were the most common type of cells used in preclinical studies (n = 15) and EVs were commonly isolated from MSCs (n = 3). Overall, both MSCs and EVs showed improvements in ocular inflammation (seen on fundoscopy/slit lamp and histology) and electroretinogram outcomes. Overall, MSC and MSC-derived EVs shown great potential as therapeutic agents for treating uveitis. Unfortunately, small sample size, risk of selection/performance bias, and lack of standardized cell harvesting or delivery protocols are some factors which limits clinical translation. Large scaled, randomized preclinical studies are required to understand the full potential of MSCs for treating uveitis.

Stem cell therapeutics and gene therapy for neurologic disorders

Rapid advances in biological knowledge and technological innovation have greatly advanced the fields of stem cell and gene therapies to combat a broad spectrum of neurologic disorders. Researchers are currently exploring a variety of stem cell types (e.g., embryonic, progenitor, induced pluripotent) and various transplantation strategies, each with its own advantages and drawbacks. Similarly, various gene modification techniques (zinc finger, TALENs, CRISPR-Cas9) are employed with various delivery vectors to modify underlying genetic contributors to neurologic disorders. While these two individual fields continue to blaze new trails, it is the combination of these technologies which enables genetically engineered stem cells and vastly increases investigational and therapeutic opportunities. The capability to culture and expand stem cells outside the body, along with their potential to correct genetic abnormalities in patient-derived cells or enhance cells with extra gene products, unleashes the full biological potential for innovative, multifaceted approaches to treat complex neurological disorders. In this review, we provide an overview of stem cell and gene therapies in the context of neurologic disorders, highlighting recent advances and current shortcomings, and discuss prospects for future therapies in clinical settings.

Understanding the multi-functionality and tissue-specificity of decellularized dental pulp matrix hydrogels for endodontic regeneration

Dental pulp is the only soft tissue in the tooth which plays a crucial role in maintaining intrinsic multi-functional behaviors of the dentin-pulp complex. Nevertheless, the restoration of fully functional pulps after pulpitis or pulp necrosis, termed endodontic regeneration, remained a major challenge for decades. Therefore, a bioactive and in-situ injectable biomaterial is highly desired for tissue-engineered pulp regeneration. Herein, a decellularized matrix hydrogel derived from porcine dental pulps (pDDPM-G) was prepared and characterized through systematic comparison against the porcine decellularized nerve matrix hydrogel (pDNM-G). The pDDPM-G not only exhibited superior capabilities in facilitating multi-directional differentiation of dental pulp stem cells (DPSCs) during 3D culture, but also promoted regeneration of pulp-like tissues after DPSCs encapsulation and transplantation. Further comparative proteomic and transcriptome analyses revealed the differential compositions and potential mechanisms that endow the pDDPM-G with highly tissue-specific properties. Finally, it was realized that the abundant tenascin C (TNC) in pDDPM served as key factor responsible for the activation of Notch signaling cascades and promoted DPSCs odontoblastic differentiation. Overall, it is believed that pDDPM-G is a sort of multi-functional and tissue-specific hydrogel-based material that holds great promise in endodontic regeneration and clinical translation. STATEMENT OF SIGNIFICANCE: Functional hydrogel-based biomaterials are highly desirable for endodontic regeneration treatments. Decellularized extracellular matrix (dECM) preserves most extracellular matrix components of its native tissue, exhibiting unique advantages in promoting tissue regeneration and functional restoration. In this study, we prepared a porcine dental pulp-derived dECM hydrogel (pDDPM-G), which exhibited superior performance in promoting odontogenesis, angiogenesis, and neurogenesis of the regenerating pulp-like tissue, further showed its tissue-specificity compared to the peripheral nerve-derived dECM hydrogel. In-depth proteomic and transcriptomic analyses revealed that the activation of tenascin C-Notch axis played an important role in facilitating odontogenic regeneration. This biomaterial-based study validated the great potential of the dental pulp-specific pDDPM-G for clinical applications, and provides a springboard for research strategies in ECM-related regenerative medicine.

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 differentiation 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 momentum, especially in light of findings such as these.

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.

Traditional and emerging strategies using hepatocytes for pancreatic regenerative medicine

Although pancreas and islet cell transplantation are the only ways to prevent the late complications of insulin-dependent diabetes, a shortage of donors is a major obstacle to tissue and organ transplantation. Stem cell therapy is an effective treatment for diabetes and other pancreatic-related diseases, which can be achieved by inducing their differentiation into insulin-secreting cells. The liver is considered an ideal source of pancreatic cells due to its similar developmental origin and strong regenerative ability as the pancreas. This article reviews the traditional and emerging strategies using hepatocytes for pancreatic regenerative medicine and evaluates their advantages and challenges. Gene reprogramming and chemical reprogramming technologies are traditional strategies with potential to improve the efficiency and specificity of cell reprogramming and promote the transformation of hepatocytes into islet cells. At the same time, organoid technology, as an emerging strategy, has received extensive attention. Biomaterials provide a three-dimensional culture microenvironment for cells, which helps improve cell survival and differentiation efficiency. In addition, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 gene editing technology has brought new opportunities and challenges to the development of organoid technology.

Biomaterial engineering for cell transplantation

The current paradigm of medicine is mostly designed to block or prevent pathological events. Once the disease-led tissue damage occurs, the limited endogenous regeneration may lead to depletion or loss of function for cells in the tissues. Cell therapy is rapidly evolving and influencing the field of medicine, where in some instances attempts to address cell loss in the body. Due to their biological function, engineerability, and their responsiveness to stimuli, cells are ideal candidates for therapeutic applications in many cases. Such promise is yet to be fully obtained as delivery of cells that functionally integrate with the desired tissues upon transplantation is still a topic of scientific research and development. Main known impediments for cell therapy include mechanical insults, cell viability, host's immune response, and lack of required nutrients for the transplanted cells. These challenges could be divided into three different steps: 1) Prior to, 2) during the and 3) after the transplantation procedure. In this review, we attempt to briefly summarize published approaches employing biomaterials to mitigate the above technical challenges. Biomaterials are offering an engineerable platform that could be tuned for different classes of cell transplantation to potentially enhance and lengthen the pharmacodynamics of cell therapies.