Regenerative Engineering and Translational Medicine最新文献

Purpose: Silk fibroin-based biomaterials have shown utility across regenerative medicine applications due to their ability to provide robust mechanical support and deliver bioactive cargo. To achieve diverse functions, fibroin can be fabricated into material formats with varied morphology including sponge-like scaffolds and microparticles. This study investigates the potential of a dual-component silk fibroin system (particle-laden sponges) to enable two-phase controlled release and assesses the impact of cytokine release on RAW 264.7 polarization.

Methods: Silk fibroin microparticles (SFMPs) were prepared through phase separation from PVA before being combined with aqueous fibroin polymer solution at desired mass ratios. This solution was frozen and lyophilized to form a particle-laden sponge. The sponge was then water annealed to induce crystallinity at a set temperature. Sponge morphology was assessed with SEM and crystallinity was assessed with FTIR. In vitro accelerated degradation studies were used to identify candidate formulations for functional release experiments. For functional release analysis, M1 and M2 promoting cytokines were loaded into the sponge and the particle portions, respectively. Cytokine release was assessed using ELISA and using RT-qPCR, the polarization state of RAW 264.7 cells was captured following 1 and 3 days of incubation with the material.

Results: Both formulation and temperature during water annealing were found to impact morphology and total crystalline content. Degradation studies showed disruption of the sponge like structures prior to SFMP degradation, indicating a potential for a multiphase controlled release platform. RAW 264.7 cells showed a polarization switch from M1 to M2 in line with hypothesized rates of release from the particle-laden sponge.

Conclusion: This study demonstrated the tunability of a dual-component silk fibroin sponge, while also establishing its potential as a multiphase controlled release platform to modulate immune interactions in future in vivo studies.

Surface modification of biomaterials, particularly by adding bioactive coatings, enhances cell-material interactions at the nanoscale, improving implant performance at the macroscale. One approach involves gene delivery via surface-bound coatings, allowing for controlled local release of viral particles. However, viral gene delivery systems, such as lentiviral vectors, face challenges in precision targeting and transduction efficiency. To address these, a bio-orthogonal coating was developed and used on titanium using chemical vapor deposition (CVD) polymerization. Co-presenting a cell-binding peptide and immobilized lentiviral particles on the surface of Ti increased gene delivery efficiency by directing cells to the surface, making them easier to transduce. Specifically, a poly[(4-(3,4dibromomaleimide)-p-xylylene)-co-(4-pentafluorophenol ester-p-xylylene)] coating was prepared using CVD polymerization on Ti discs as a bio-orthogonal layer to tether lentiviral particles delivering GJA1, the gene for the gap junction protein Connexin 43 (Cx43) and the Mesenchymal stem cell (MSC) binding peptide, DPIYALSWSGMA. The polymer coating exhibited high binding efficiency for both lentivirus and peptide, allowing for precise microcontact printing. Immobilized lentiviral transduction efficiency matched that in supernatant, with co-delivery increasing transduction efficiency by 35%. The biorthogonal coating boosted MSC binding 2.7-fold, leading to a density-dependent rise in cell-cell communication. High-density seeding enabled gap junction formation, while Cx43 transduction increased intercellular communication by 36%. In low-density culture, transduction led to an 84% increase in cell-cell communication within 4h of in vitro culture. This work presents a simple, repeatable surface modification method for biomolecular immobilization, combining engineered viral vectors and peptides to enhance gene delivery approaches.

Fibroblast growth factor II (FGF2), or basic fibroblast growth factor (bFGF), is an important regulator in bone and craniofacial development. FGF2 regulates cell survival, proliferation, migration, multilineage differentiation, and stemness in stromal cells. While there is broad interest in utilizing FGF2 for bone and craniofacial tissue repair and regeneration, the literature and reported data are often inconsistent or even controversial due to its multifunctional nature. Therefore, the outcomes are dependent on dose, duration, timing of administration, spatiotemporal pattern of the FGF2 delivery, and the microenvironment. This review paper aims to discuss FGF2 signaling and its related pathways, as well as mechanisms in vitro, in vivo, and in clinical applications of FGF2 in inducing osteogenic differentiation of human mesenchymal stromal cells (hMSCs) for craniofacial bone regeneration.

The biomedical research of nucleic acids as therapeutics and their medical applications has been steadily progressing. Identifying the fundamental regulatory roles of nucleic acids and their potential use in the medical field is of major pursuit in current and future research endeavors. Research into nucleic acids for the treatment of vascular diseases has been an emerging avenue as nucleic acids have the ability to treat a variety of pathologies including atherosclerosis. A large part of the translational research in relation to nucleic acids is the development and optimization of drug delivery technologies that can harness the full potential of these molecules, providing untapped, novel therapeutic agents. Specifically, the use of biomaterial delivery systems, consisting of polymers, lipids, and inorganic materials, allows for the protection of nucleic acid therapeutics to promote targeting to regions of vascular damage. While the relevance of nucleic acid therapeutics has been well documented, their functionality for diseases affecting the peripheral vasculature, and the need for biomaterials systems capable of improving their efficacy, has been lacking. This review aims to provide an overview of the biomaterial technologies tested for nucleic acid delivery, relative to the science of applied vascular tissue engineering.

Purpose: Biomaterial scaffolds capable of controlled release of bioactive molecules hold significant potential in tissue engineering, offering a promising avenue to enhance tissue regeneration. They provide localized and sustained delivery of biological cues to direct stem cell differentiation while creating a three-dimensional microenvironment that supports cell adhesion and growth.

Methods: In this study, we utilized reverse micelle sugar glass nanoparticles (SGnPs), previously developed by our team, to encapsulate the chondrogenic growth factor TGFB1. This approach aimed to preserve the bioactivity of these molecules before their release. The TGFB1-SGnPs were directly incorporated into electrospun fibrous scaffolds, engineered specifically to ensure the sustained release of the growth factor during the culture of human bone marrow-derived mesenchymal stem/stromal cells (BMSCs).

Results: TGFB1 was released in a sustained manner over 39 days from TGFB1-SGnP-incorporated fibrous scaffolds, made from poly (ε-caprolactone), poly (d-lactic acid) (PLA), and poly (lactic-co-glycolic acid). Among these formulations, the PLA-based scaffolds demonstrated the highest cumulative TGFB1 release over the study period. In vitro cell studies demonstrated that TGFB1-SGnP-PLA fibrous scaffolds supported the proliferation of BMSCs and enhanced chondrogenic differentiation. Transcript expression analysis of BMSCs seeded on TGFB1-SGnP-PLA fibrous scaffolds induced for chondrogenesis revealed an upregulation of chondrocyte-associated markers, including SOX9, ACAN, COL2A1, and COL1A1.

Conclusion: This study demonstrates the potential of using SGnPs to protect and deliver chondrogenic induction molecules from electrospun fibrous scaffolds in a sustained manner, promoting the chondrogenic differentiation of BMSCs in cartilage tissue engineering.Lay Summary.Researchers have developed advanced biomaterial scaffolds that release bioactive molecules to enhance tissue regeneration. These "smart scaffolds" provide a three-dimensional environment for cell growth and localized cues to support biological functions. Utilizing sugar glass nanoparticles (SGnPs) to encapsulate growth factors like TGFB1, electrospun fibrous scaffolds incorporating TGFB1-SGnPs were crafted to assess their effectiveness in supporting the activity of human bone marrow-derived mesenchymal stem/stromal cells (BMSCs). Results showed that TGFB1, particularly from TGFB1-SGnP-PLA scaffolds, significantly promoted BMSC proliferation and chondrogenic differentiation, as evidenced by increased markers associated with cartilage cells. This innovative approach demonstrates considerable potential for advancing cartilage tissue engineering and offers a new therapeutic strategy for conditions such as osteoarthritis, enhancing tissue repair and regeneration.

Purpose: Non-healing chronic wounds in diabetic patients pose a significant health and economic burden. We have previously shown that the citrate-based thermoresponsive macromolecule poly(polyethylene glycol citrate-co-N-isopropylacrylamide) displaying the laminin-derived peptide A5G81 (A5G81-PPCN) accelerates wound closure when used as a regenerative dressing in diabetic mice. Although results are promising, A5G81-PPCN should be evaluated in a relevant large animal model of impaired wound healing. While several large animal models of impaired wound healing have been reported, the Ossabaw miniature swine is unique because it exhibits the full spectrum of metabolic syndrome features and vascular complications that are most similar to those of humans. In this study we investigated whether alloxan-induced diabetic Ossabaw miniature swine would manifest impaired wound healing similar to that observed in humans and evaluated the efficacy and safety of A5G81-PPCN, PPCN, and the commercial dressing Promogran Prisma™.

Methods: After at least 5 months of hyperglycemia (≥ 200 mg/dL) eight full-thickness wounds (3 cm × 3 cm × 5 mm) were created on the back of each animal. Weekly dressing changes, treatment reapplications, and monitoring of blood glucose and weight were performed for 8 weeks post-wounding.

Results: Diabetic Ossabaw swine exhibited notable delayed healing compared to non-diabetic counterparts, validating the model's relevance. Moreover, PPCN and A5G81-PPCN exhibited accelerated wound closure rates relative to Promogran Prisma™.

Conclusion: This research underscores the potential for this citrate-based thermoresponsive macromolecule to address an unmet clinical need for healing wounds in diabetic patients and highlights Ossabaw swine as a new model for studying impaired wound healing in diabetes.

Lay summary: Non-healing chronic wounds in diabetic patients pose a significant health and economic burden. We previously developed a unique regenerative dressing called A5G81-PPCN, made from a temperature-sensitive material with a peptide component that accelerates wound healing in diabetic mice. To test this dressing in a clinically relevant model, we used Ossabaw miniature pigs, which mimic human metabolic syndrome and blood vessel complications. After inducing diabetes in these pigs, we created skin wounds and monitored healing for eight weeks. Results show that A5G81-PPCN and PPCN dressings accelerate wound closure relative to a commercial dressing, Promogran Prisma™. This research suggests that A5G81-PPCN could be a valuable new approach to help heal diabetic wounds and positions the Ossabaw pig as an important model for studying diabetic wound healing.

Supplementary information: The online version contains supplementary material available at 10.1007/s40883-025-00425-w.

Purpose: Pancreatic cancer (PC) is a highly lethal malignancy and lacks effective treatments. Current chemotherapies, including gemcitabine (Gem) in combination treatment regimens, produce dose-limiting toxicity, drug resistance, and ultimately limited improvement in the overall survival of PC patients. Niclosamide (Nic), a clinically safe FDA-approved anthelmintic drug has been shown to have anti-cancer properties; however, its limited bioavailability makes Nic largely ineffective as a therapeutic agent. To address this challenge, we have developed a novel combination therapy of Gem with the repurposed drug, Nic, loaded in biodegradable polyanhydride nanoparticles (NicNp), as an effective treatment option for PC.

Methods: We synthesized and characterized NicNp in vitro and evaluated their biodistribution and efficacy in xenograft and syngeneic pancreatic tumor models in mice.

Results: The biodistribution study indicated that NicNp accumulated in high concentrations in the pancreatic tumors of the mice with C_max of 138 ± 74.1 µg Nic/g tissue. NicNp treatment, in combination with Gem, worked synergistically to reduce the dose of gemcitabine required to kill pancreatic cancer cells in vitro, two-fold. Additionally, the pancreatic tumor burden in the mouse models was significantly reduced, while survival was significantly increased when mice bearing pancreatic tumors were treated with the combination of NicNp and Gem.

Conclusions: This study demonstrates the potential for effective repurposing Nic via nanoformulations in combination with Gem to improve PC treatment efficacy.

Lay summary: Pancreatic cancer (PC) ranks among the most lethal types of cancer, with largely ineffective current treatments and toxic side effects in patients. Niclosamide is an FDA-approved anti-parasitic drug with minimal side effects, that has shown some anti-cancer properties. However, it is not effectively absorbed in the body. We produced polymer nanoparticles to deliver niclosamide effectively to treat pancreatic tumors in mice in combination with the chemotherapeutic gemcitabine. This combination treatment led to PC tumor reduction and increased the survival, demonstrating that niclosamide encapsulated in nanoparticles in combination with gemcitabine has the potential to be a more effective treatment for PC.

Graphical abstract:

Supplementary information: The online version contains supplementary material available at 10.1007/s40883-025-00394-0.

Abstract: Influenza virus is a persistent source of morbidity and moribundity, and effective disease control requires ever-evolving effective vaccines. In this work, we evaluate the safety and biocompatibility of two novel polymeric particle-based influenza vaccines. Mice were immunized either intranasally or subcutaneously with these two formulations and examined at 1 h, 1 day, and 14 days post-immunization for histopathology in liver, kidneys, and lungs and serum biomarker analysis. Mice that received an intranasal vaccination were also observed for pulmonary disruption via whole body plethysmography. Examination of tissues post-immunization found only limited inflammation, with no difference observed in plethysmography measurements and no serum biomarkers (e.g., AST, AlkPhos) indicating tissue damage. Collectively, these data support the conclusion that these polymeric particle-based influenza vaccine formulations were well tolerated by the animals and did not induce any adverse side effects.

Lay summary: Particle-based influenza vaccines were safety tolerated by mice and did not induce any adverse side effects.

Supplementary information: The online version contains supplementary material available at 10.1007/s40883-025-00473-2.

Purpose: The extracellular environment is critical for cell migration in three-dimensions (3D), which has been understudied when compared to cell migration on two-dimensional (2D) substrates. In 3D, cells must degrade or remodel their surroundings to overcome barriers to migration or find paths that act as migration routes.

Methods: We performed a literature search for studies related to the engineering of hydrogels to understand and control cell migration.

Results: This review highlights the cell-intrinsic machinery that is required for migration, describes how cell migration can be modeled in vitro, and provides examples where hydrogels have been designed with permissive extracellular cues that enhance cell migration for biomedical applications.

Conclusions: Hydrogels can be engineered to mimic many features of the extracellular space to help us better understand the interplay between cells and their environment and interpret how these complex processes support or limit cell migration. With this understanding, hydrogels can be designed to guide cellular migration, particularly in the context of tissue repair and regenerative medicine.

Lay summary: Cell movement is important in both healthy and diseased tissues. An understanding of how cells migrate and the development of methods to control their migration can be utilized to improve patient therapies in the future in applications such as tissue repair and regeneration. Hydrogels are water-swollen materials that mimic many features of tissues. This allows their use to understand how cells respond to various features in their environment, as well as for therapeutic materials in tissue repair. This review highlights advances on these topics.

Abstract: Pediatric high-grade gliomas (pHGGs) are among the most devastating cancers in children. These tumors have remained largely incurable, despite the many approaches that have been applied for their treatment. Here we use scaffolds of glycopeptide nanostructures designed for regenerative therapies to bind and present bone morphogenetic protein (BMP-4) in vivo to differentiate glioma cells and render them more susceptible to traditional chemotherapeutics. Interestingly, we discovered that the presentation of BMP-4 on these glycopeptide structures alone, without the use of a traditional chemotherapy, resulted in reduced tumor growth and enhanced survival in an orthotopic xenograft pediatric high-grade glioma tumor mouse model. Thus, this strategy has the potential to serve as a future chemotherapy-free platform for treating pHGGs which may have significantly reduced comorbidities.

Lay summary: Pediatric glioblastoma (pGBM) is an aggressive brain cancer with poor survival rates despite surgery, radiation, and chemotherapy. The growth factor BMP-4 shows promise as a treatment, but its short half-life limits its potential as a future pGBM therapeutic. We developed nanostructures made from sugar-inspired molecules known as glycopeptide amphiphile molecules (gPA) that can bind, stabilize, and enhance the activity of BMP-4. When presented on gPA, BMP-4 directed pGBM cells to become less stem cell-like which slowed tumor growth in a mouse model. This approach highlights a potential strategy to improve BMP-4 delivery to advance therapeutic options for children with pGBM.

Future work: Development of chemically scalable glycosylated supramolecular structures, such as the one described here, can be used to bind and present BMP-4 as well as other proteins for future drug delivery applications in the nervous system and beyond. Future research should also investigate how these therapies can be co-administered with chemotherapeutics.

Graphical abstract:

Supplementary information: The online version contains supplementary material available at 10.1007/s40883-025-00543-5.