Lyophilized Platelet-Rich Fibrin Exudate-Loaded Carboxymethyl Chitosan/GelMA Hydrogel for Efficient Bone Defect Repair

Bone Immune Microenvironment-Modulating Naringin Carbon Dot Complex Hydrogel with ROS-Scavenging and Antibacterial Properties for Enhanced Bone Repair

Bone regeneration involves complex interactions between immune cells and bone lineage cells. Osteoimmunomodulatory strategies that optimize the bone regenerative microenvironment by regulating immune cell behavior represent a key area of research focused on bone repair. In this study, naringin-based copper carbon dots (Nar-CuCDs) were synthesized using the hydrothermal method. Subsequently, Nar-CuCDs were loaded onto a double cross-linked hydrogel (Gel) constructed from acrylamide, sodium alginate oxide, and carboxymethyl chitosan to create a Nar-CuCDs/Gel composite hydrogel. The in vitro experiments indicated that the composite hydrogel had excellent reactive oxygen species (ROS) scavenging properties, anti-inflammatory properties, and osteoimmunomodulatory activity. Nar-CuCDs/Gel could induce anti-inflammatory phenotypic (M2-type) expression in macrophages in an inflammatory environment, regulate the bone immune microenvironment to promote osteogenic differentiation of rBMSCs, thus realizing the synergistic regulation of "immune-osteogenic" for bone repair. In addition, it effectively suppressed the survival of S. aureus and E. coli. Results of in vivo studies showed that the composite hydrogel could accelerate bone regeneration. In conclusion, Nar-CuCDs/Gel potently promoted the repair of bone defects by simultaneously optimizing the immune microenvironment and enhancing osteogenic activity. This strategy of synergistic regulation of "immune-osteogenic" provided insights for bone regeneration research.

Application of Platelet-Rich Plasma-Based Scaffolds in Soft and Hard Tissue Regeneration

Platelet-rich plasma (PRP) is a blood product with higher platelet concentrations than whole blood, offering controlled delivery of growth factors (GFs) for regenerative medicine. PRP plays pivotal roles in tissue restoration mechanisms, including angiogenesis, fibroblast proliferation, and extracellular matrix development, making it applicable across various regenerative medicine treatments. Despite promising results in different tissue injuries, challenges such as short half-life and rapid deactivation by proteases persist. To address these challenges, biomaterial-based delivery scaffolds, such as sponges or hydrogels, have been investigated. Current studies exhibit that PRP-loaded scaffolds fix these issues due to the sustained release of GFs. In this regard, given the widespread application of PRP in clinical studies, the use of PRP-loaded scaffolds has drawn significant consideration in tissue engineering (TE). Therefore, this review briefly introduces PRP as a rich origin of GFs, its classification, and preparation methods and discusses PRP applications in regenerative medicine. This study also emphasizes and reviews the latest research on the using scaffolds for PRP delivery in diverse fields of TE, including skin, bone, and cartilage repair.

Photoresponsive Blood-Derived Protein Hydrogels Packed with Bioactive Carbon Dots Modulate Mitochondrial Homeostasis and Reprogram Metabolism for Chronic Wound Healing in Diabetes

Autologous platelet concentrates (APC) represent a class of personalized regenerative materials for vascularized tissue regeneration. However, shortcomings including poor controllability of gel formation, lack of reactive oxygen species (ROS) scavenging ability, and deficient anti-inflammatory capacity restrict the tissue healing outcomes of APC. This study proposes an APC-based synergistic platform (CurCDs@iPRF-MA) for the treatment of chronic wounds in diabetes. Such a platform is composed of injectable platelet-rich fibrin (iPRF), gelatin methacryloyl (GelMA), and a carbogenic nanodrug from curcumin (CurCDs) that is injectable before the light-induced gel formation process, greatly facilitating the clinical applications of APC. Significantly, CurCDs@iPRF-MA can modulate the mitochondrial homeostasis under inflammatory conditions, activate the oxidative phosphorylation (OXPHOS) program, and regulate the diabetic microenvironment through metabolic reprogramming to achieve macrophage phenotype regulation and ROS elimination, as well as promote vascularization by releasing autologous growth factors, dramatically improving the healing efficacy of the chronic wounds in diabetes. This study offers a practical and effective approach to developing spatiotemporally controllable and multifunctional APC-based hydrogels for highly effective tissue regeneration.

Peripheral nerve regeneration with 3D printed bionic double-network conductive scaffold based on GelMA/chitosan/polypyrrole

Peripheral nerve injury (PNI) is a serious condition with limited surgical treatment options available. Conductive hydrogels have emerged as a promising alternative due to their ability to facilitate electrical signal exchange between cells and replicate the physiological microenvironment of electroactive tissues. Three-dimensional (3D) printing offers an innovative approach for fabricating neural scaffolds with precise structures and complex spatial architectures. In this study, we introduce a novel dual-bioink 3D printing strategy that integrates synthetic and natural materials to construct stable biomimetic neural tissue structures. The base bioink, comprising gelatin methacrylate (GelMA), chitosan (CS), and the conductive polymer polypyrrole (PPy), serves as a physical support network. It offers conductive pathways, promote cell growth, and ensures long-term structural integrity. The secondary bioink is a cell-loaded biodegradable gel-gelatin, which enables for precise cell deposition within the base network through a hybrid printing technique. The composite scaffold was evaluated for its mechanical properties, cytotoxicity, and ability to support neural differentiation. The results demonstrated that the 3D-printed neural network scaffold effectively promoted the neural differentiation and axon regeneration of PC-12 cells and HT-22 cells. These findings highlight its strong potential for facilitating neural functional recovery, positioning it as a promising candidate material for the treatment of PNI patients.

Gelatin methacryloyl-phenylboronic acid/Hydroxyadamantane self-healing microgels for the periodontitis treatment by promoting alveolar bone regeneration

Periodontitis is a chronic inflammatory condition mainly caused by the interaction between the host immune system and periodontal tissue pathogens, and may lead to consequences, such as alveolar bone defects and tooth loss. Incomplete bacterial removal, persistent inflammation and high reactive oxygen species (ROS) environment are the main challenges for periodontal tissue repair and alveolar bone regeneration. In this study, an injectable composite microgel (Gelatin methacryloyl-Phenylboronic acid/Hydroxyadamantane, GPH) loaded with antimicrobial peptide (AMP) and cerium dioxide (CeO2) microspheres was developed to achieve a synergistic function of bacteriostasis, immunomodulation, and ROS removal. In vitro studies had shown that the composite microgel had an inhibitory rate of >99 % against E. coli, S. aureus and P. gingivalis and scavenged DPPH with a rate of 87.1 % ± 2.0 %, exhibiting excellent antibacterial and antioxidant properties. In addition, it was able to promote macrophage phenotypic shift from M1-type to M2-type and reduce ROS levels, and also had excellent biocompatibility. Mechanistically, the composite microgel was subjected to transcriptome sequencing analysis of gene expression levels and signaling pathways in BMSC cells, and the results showed that the microgel played an important role in regulating the PI3K-Akt and chemokine signaling pathways, which in turn inhibited the expression of inflammatory factors. In vivo the effect of composite microgel on periodontal tissue repair and alveolar bone regeneration was verified by infected alveolar bone defect model. The results showed that after 4 weeks of using the composite microgel, the bone volume per unit of tissue volume of the alveolar bone, the thickness of bone trabeculae, and the bone mineral density reached 25.94 % ± 0.03 %, 0.14 mm ± 0.01 mm, and 0.442 g/cm3 ± 0.003 g/cm3, respectively, while those of the control group were 22.3 % ± 0.29 %, 0.07 mm ± 0.02 mm, and 0.236 g/cm3 ± 0.059 g/cm3, respectively, and the use of the composite microgel resulted in significantly better repair results than the control group. In addition, pro-inflammatory factors were significantly suppressed and inflammation levels were significantly reduced. Overall, this composite microgel showed great potential in reducing inflammation levels and promoting alveolar bone regeneration, providing an innovative approach to the treatment of periodontitis.

Physical stimuli-responsive DNA hydrogels: design, fabrication strategies, and biomedical applications

Physical stimuli-responsive DNA hydrogels hold immense potential for tissue engineering due to their inherent biocompatibility, tunable properties, and capacity to replicate the mechanical environment of natural tissue, making physical stimuli-responsive DNA hydrogels a promising candidate for tissue engineering. These hydrogels can be tailored to respond to specific physical triggers such as temperature, light, magnetic fields, ultrasound, mechanical force, and electrical stimuli, allowing precise control over their behavior. By mimicking the extracellular matrix (ECM), DNA hydrogels provide structural support, biomechanical cues, and cell signaling essential for tissue regeneration. This article explores various physical stimuli and their incorporation into DNA hydrogels, including DNA self-assembly and hybrid DNA hydrogel methods. The aim is to demonstrate how DNA hydrogels, in conjunction with other biomolecules and the ECM environment, generate dynamic scaffolds that respond to physical stimuli to facilitate tissue regeneration. We investigate the most recent developments in cancer therapies, including injectable DNA hydrogel for bone regeneration, personalized scaffolds, and dynamic culture models for drug discovery. The study concludes by delineating the remaining obstacles and potential future orientations in the optimization of DNA hydrogel design for the regeneration and reconstruction of tissue. It also addresses strategies for surmounting current challenges and incorporating more sophisticated technologies, thereby facilitating the clinical translation of these innovative hydrogels.

Static Topographical Cue Combined with Dynamic Fluid Stimulation Enhances the Macrophage Extracellular Vesicle Yield and Therapeutic Potential for Bone Defects

Extracellular vesicles (EVs) hold promise for tissue regeneration, but their low yield and limited therapeutic efficacy hinder clinical translation. Bioreactors provide a larger culture surface area and stable environment for large-scale EV production, yet their ability to enhance EV therapeutic efficacy is limited. Physical stimulation, by inducing cell differentiation and modulating EV cargo composition, offers a more efficient, cost-effective, and reproducible approach compared to the cargo loading of EVs and biochemical priming of parental cells. Herein, the effects of a 3D-printed perfusion bioreactor with a topographical cue on the macrophage EV yield and bioactivity were assessed. The results indicate that the bioreactor increased the EV yield 12.5-fold and enhanced bioactivity in promoting osteogenic differentiation and angiogenesis via upregulated miR-210-3p. Mechanistically, fluid shear stress activates Piezo1, triggering Ca2+ influx and Yes-associated protein (YAP) nuclear translocation, promoting EV secretion and enhancing macrophage M2 polarization in conjunction with morphological changes guided by aligned topography. Moreover, a porous electrospun membrane-hydrogel composite scaffold loaded with bioreactor-derived EVs exhibited outstanding efficacy in promoting osteogenic differentiation and angiogenesis in a rat cranial defect model. This study presents a scalable, cost-effective, and stable platform for the production of therapeutic EVs, potentially overcoming key challenges in translating EV-based therapies to the clinic.

Preparation of photo-crosslinked microalgae-carboxymethyl chitosan composite hydrogels for enhanced wound healing

Integrating microalgae into wound dressings has proven effective in promoting chronic wound healing through photosynthesis-induced oxygen release. However, challenges such as high crosslinking temperatures and prolonged gel molding processes limit microalgae growth and reduce the overall therapeutic impact. In this work, inspired by cell-symbiotic photo-crosslinked hydrogels, we present a novel photo-crosslinked microalgae carboxymethyl chitosan composite hydrogel. This hydrogel completes crosslinking at room temperature within 30 s, enhancing chronic wound healing. The composite gel incorporates photosynthesizing unicellular microalgae (Chlamydomonas reinhardtii) and the antimicrobial agent ciprofloxacin during preparation. In light, the gel continues to photosynthesize, releasing oxygen while simultaneously acting as an antibacterial agent. This dual action results in the upregulation of CD31 and VEGFA levels and the downregulation of HIF-1α levels in diabetic wounds. The wound closure rate reached approximately 96.70 % on day 12 in the composite gel group, compared to only 78.98 % in the control group. Therefore, the composite gel promotes healing by reducing local hypoxia, encouraging angiogenesis, and lowering infection risk. These results suggest that photo-crosslinked microalgae composite gels provide an effective strategy for localized oxygen delivery to promote wound healing and offer a viable method for rapidly preparing living biomaterials under suitable conditions.

Advanced Hybrid Strategies of GelMA Composite Hydrogels in Bone Defect Repair

To date, severe bone defects remain a significant challenge to the quality of life. All clinically used bone grafts have their limitations. Bone tissue engineering offers the promise of novel bone graft substitutes. Various biomaterial scaffolds are fabricated by mimicking the natural bone structure, mechanical properties, and biological properties. Among them, gelatin methacryloyl (GelMA), as a modified natural biomaterial, possesses a controllable chemical network, high cellular stability and viability, good biocompatibility and degradability, and holds the prospect of a wide range of applications. However, because they are hindered by their mechanical properties, degradation rate, and lack of osteogenic activity, GelMA hydrogels need to be combined with other materials to improve the properties of the composites and endow them with the ability for osteogenesis, vascularization, and neurogenesis. In this paper, we systematically review and summarize the research progress of GelMA composite hydrogel scaffolds in the field of bone defect repair, and discuss ways to improve the properties, which will provide ideas for the design and application of bionic bone substitutes.

Developing fibrin-based biomaterials/scaffolds in tissue engineering

Tissue engineering technology has advanced rapidly in recent years, offering opportunities to construct biologically active tissues or organ substitutes to repair or even enhance the functions of diseased tissues and organs. Tissue-engineered scaffolds rebuild the extracellular microenvironment by mimicking the extracellular matrix. Fibrin-based scaffolds possess numerous advantages, including hemostasis, high biocompatibility, and good degradability. Fibrin scaffolds provide an initial matrix that facilitates cell migration, differentiation, proliferation, and adhesion, and also play a critical role in cell-matrix interactions. Fibrin scaffolds are now widely recognized as a key component in tissue engineering, where they can facilitate tissue and organ defect repair. This review introduces the properties of fibrin, including its composition, structure, and biology. In addition, the modification and cross-linking modes of fibrin are discussed, along with various forms commonly used in tissue engineering. We also describe the biofunctionalization of fibrin. This review provides a detailed overview of the use and applications of fibrin in skin, bone, and nervous tissues, and provides novel insights into future research directions for clinical treatment.

Platelet-rich fibrin (PRF) modified nano-hydroxyapatite/chitosan/gelatin/alginate scaffolds increase adhesion and viability of human dental pulp stem cells (DPSC) and osteoblasts derived from DPSC

Bone tissue regeneration strategies have incorporated the use of natural polymers, such as hydroxyapatite (nHA), chitosan (CH), gelatin (GEL), or alginate (ALG). Additionally, platelet concentrates, such as platelet-rich fibrin (PRF) have been suggested to improve scaffold biocompatibility. This study aimed to develop scaffolds composed of nHA, GEL, and CH, with or without ALG and lyophilized PRF, to evaluate the scaffold's properties, growth factor release, and dental pulp stem cells (DPSC), and osteoblast (OB) derived from DPSC viability. Four scaffold variations were synthesized and lyophilized. Then, degradation, swelling profiles, and morphological analysis were performed. Furthermore, PDGF-BB and FGF-B growth factors release were quantified by ELISA, and cytotoxicity and cell viability were evaluated. The swelling and degradation profiles were similar in all scaffolds, with pore sizes ranging between 100 and 250 μm. FGF-B and PDGF-BB release was evidenced after 24 h of scaffold immersion in cell culture medium. DPSC and OB-DPSC viability was notably increased in PRF-supplemented scaffolds. The nHA-CH-GEL-PRF scaffold demonstrated optimal physical-biological characteristics for stimulating DPSC and OB-DPSC cell viability. These results suggest lyophilized PRF improves scaffold biocompatibility for bone tissue regeneration purposes.

Unveiling the versatility of gelatin methacryloyl hydrogels: a comprehensive journey into biomedical applications

Gelatin methacryloyl (GelMA) hydrogels have gained significant recognition as versatile biomaterials in the biomedical domain. GelMA hydrogels emulate vital characteristics of the innate extracellular matrix by integrating cell-adhering and matrix metalloproteinase-responsive peptide motifs. These features enable cellular proliferation and spreading within GelMA-based hydrogel scaffolds. Moreover, GelMA displays flexibility in processing, as it experiences crosslinking when exposed to light irradiation, supporting the development of hydrogels with adjustable mechanical characteristics. The drug delivery landscape has been reshaped by GelMA hydrogels, offering a favorable platform for the controlled and sustained release of therapeutic actives. The tunable physicochemical characteristics of GelMA enable precise modulation of the kinetics of drug release, ensuring optimal therapeutic effectiveness. In tissue engineering, GelMA hydrogels perform an essential role in the design of the scaffold, providing a biomimetic environment conducive to cell adhesion, proliferation, and differentiation. Incorporating GelMA in three-dimensional printing further improves its applicability in drug delivery and developing complicated tissue constructs with spatial precision. Wound healing applications showcase GelMA hydrogels as bioactive dressings, fostering a conducive microenvironment for tissue regeneration. The inherent biocompatibility and tunable mechanical characteristics of GelMA provide its efficiency in the closure of wounds and tissue repair. GelMA hydrogels stand at the forefront of biomedical innovation, offering a versatile platform for addressing diverse challenges in drug delivery, tissue engineering, and wound healing. This review provides a comprehensive overview, fostering an in-depth understanding of GelMA hydrogel's potential impact on progressing biomedical sciences.

Heterogeneous DNA hydrogel loaded with Apt02 modified tetrahedral framework nucleic acid accelerated critical-size bone defect repair

Segmental bone defects, stemming from trauma, infection, and tumors, pose formidable clinical challenges. Traditional bone repair materials, such as autologous and allogeneic bone grafts, grapple with limitations including source scarcity and immune rejection risks. The advent of nucleic acid nanotechnology, particularly the use of DNA hydrogels in tissue engineering, presents a promising solution, attributed to their biocompatibility, biodegradability, and programmability. However, these hydrogels, typically hindered by high gelation temperatures (∼46 °C) and high construction costs, limit cell encapsulation and broader application. Our research introduces a novel polymer-modified DNA hydrogel, developed using nucleic acid nanotechnology, which gels at a more biocompatible temperature of 37 °C and is cost-effective. This hydrogel then incorporates tetrahedral Framework Nucleic Acid (tFNA) to enhance osteogenic mineralization. Furthermore, considering the modifiability of tFNA, we modified its chains with Aptamer02 (Apt02), an aptamer known to foster angiogenesis. This dual approach significantly accelerates osteogenic differentiation in bone marrow stromal cells (BMSCs) and angiogenesis in human umbilical vein endothelial cells (HUVECs), with cell sequencing confirming their targeting efficacy, respectively. In vivo experiments in rats with critical-size cranial bone defects demonstrate their effectiveness in enhancing new bone formation. This innovation not only offers a viable solution for repairing segmental bone defects but also opens avenues for future advancements in bone organoids construction, marking a significant advancement in tissue engineering and regenerative medicine.

Plasma Rich in Growth Factors in Bone Regeneration: The Proximity to the Clot as a Differential Factor in Osteoblast Cell Behaviour

The osteogenic differentiation process, by which bone marrow mesenchymal stem cells and osteoprogenitors transform into osteoblasts, is regulated by several growth factors, cytokines, and hormones. Plasma Rich in Growth Factors (PRGF) is a blood-derived preparation consisting of a plethora of bioactive molecules, also susceptible to containing epigenetic factors such as ncRNAs and EVs, that stimulates tissue regeneration. The aim of this study was to investigate the effect of the PRGF clot formulation on osteogenic differentiation. Firstly, osteoblast cells were isolated and characterised. The proliferation of bone cells cultured onto PRGF clots or treated with PRGF supernatant was determined. Moreover, the gene expression of Runx2 (ID: 860), SP7 (ID: 121340), and ALPL (ID: 249) was analysed by one-step real-time quantitative polymerase chain reaction (RT-qPCR). Additionally, alkaline phosphatase (ALPL) activity determination was performed. The highest proliferative effect was achieved by the PRGF supernatant in all the study periods analysed. Concerning gene expression, the logRGE of Runx2 increased significantly in osteoblasts cultured with PRGF formulations compared with the control group, while that of SP7 increased significantly in osteoblasts grown on the PRGF clots. On the other hand, despite the fact that the PRGF supernatant induced ALPL up-regulation, significantly higher enzyme activity was detected for the PRGF clots in comparison with the supernatant formulation. According to our results, contact with the PRGF clot could promote a more advanced phase in the osteogenic process, associated to higher levels of ALPL activity. Furthermore, the PRGF clot releasate stimulated a higher proliferation rate in addition to reduced SP7 expression in the cells located at a distant ubication, leading to a less mature osteoblast stage. Thus, the spatial relationship between the PRGF clot and the osteoprogenitors cells could be a factor that influences regenerative outcomes.

Applications and prospects of microneedles in tumor drug delivery

As drug delivery devices, microneedles are used widely in the local administration of various drugs. Such drug-loaded microneedles are minimally invasive, almost painless, and have high drug delivery efficiency. In recent decades, with advancements in microneedle technology, an increasing number of adaptive, engineered, and intelligent microneedles have been designed to meet increasing clinical needs. This article summarizes the types, preparation materials, and preparation methods of microneedles, as well as the latest research progress in the application of microneedles in tumor drug delivery. This article also discusses the current challenges and improvement strategies in the use of microneedles for tumor drug delivery.

Platelet rich fibrin and simvastatin-loaded pectin-based 3D printed-electrospun bilayer scaffold for skin tissue regeneration

Designing multifunctional wound dressings is a prerequisite to prevent infection and stimulate healing. In this study, a bilayer scaffold (BS) with a top layer (TL) comprising 3D printed pectin/polyacrylic acid/platelet rich fibrin hydrogel (Pec/PAA/PRF) and a bottom nanofibrous layer (NL) containing Pec/PAA/simvastatin (SIM) was produced. The biodegradable and biocompatible polymers Pec and PAA were cross-linked to form hydrogels via Ca2+ activation through galacturonate linkage and chelation, respectively. PRF as an autologous growth factor (GF) source and SIM together augmented angiogenesis and neovascularization. Because of 3D printing, the BS possessed a uniform distribution of PRF in TL and an average fiber diameter of 96.71 ± 18.14 nm was obtained in NL. The Young's modulus of BS was recorded as 6.02 ± 0.31 MPa and its elongation at break was measured as 30.16 ± 2.70 %. The wound dressing gradually released growth factors over 7 days of investigation. Furthermore, the BS significantly outperformed other groups in increasing cell viability and in vivo wound closure rate (95.80 ± 3.47 % after 14 days). Wounds covered with BS healed faster with more collagen deposition and re-epithelialization. The results demonstrate that the BS can be a potential remedy for skin tissue regeneration.

Exploration of the Delivery of Oncolytic Newcastle Disease Virus by Gelatin Methacryloyl Microneedles

Oncolytic Newcastle disease virus is a new type of cancer immunotherapy drug. This paper proposes a scheme for delivering oncolytic viruses using hydrogel microneedles. Gelatin methacryloyl (GelMA) was synthesized by chemical grafting, and GelMA microneedles encapsulating oncolytic Newcastle disease virus (NDV) were prepared by micro-molding and photocrosslinking. The release and expression of NDV were tested by immunofluorescence and hemagglutination experiments. The experiments proved that GelMA was successfully synthesized and had hydrogel characteristics. NDV was evenly dispersed in the allantoic fluid without agglomeration, showing a characteristic virus morphology. NDV particle size was 257.4 ± 1.4 nm, zeta potential was -13.8 ± 0.5 mV, virus titer TCID50 was 107.5/mL, and PFU was 2 × 107/mL, which had a selective killing effect on human liver cancer cells in a dose and time-dependent manner. The NDV@GelMA microneedles were arranged in an orderly cone array, with uniform height and complete needle shape. The distribution of virus-like particles was observed on the surface. GelMA microneedles could successfully penetrate 5% agarose gel and nude mouse skin. Optimal preparation conditions were freeze-drying. We successfully prepared GelMA hydrogel microneedles containing NDV, which could effectively encapsulate NDV but did not detect the release of NDV.

Injectable and Photocurable Gene Scaffold Facilitates Efficient Repair of Spinal Cord Injury

RNA interference-based gene therapy has led to a strategy for spinal cord injury (SCI) therapy. However, there have been high requirements regarding the optimal gene delivery vector for siRNA-based SCI gene therapy. Here, we developed an injectable and photocurable lipid nanoparticle GelMA (PLNG) hydrogel scaffold for controlled dual siRNA delivery at the SCI wound site. The prepared PLNG scaffold could efficiently protect and retain the bioactivity of the siRNA nanocomplex. It facilitated sustainable siRNA release along with degradation in 7 days. After loading dual siRNA targeting phosphatase and tensin homologue (PTEN) and macrophage migration inhibitory factor (MIF) simultaneously, the locally administered siRNAs/PLNG scaffold efficiently improved the Basso mouse scale (BMS) score and recovered ankle joint movement and plantar stepping after treatment with only three doses. We further proved that the siRNAs/PLNG scaffold successfully regulated the activities of neurons, microglia, and macrophages, thus promoting neuron axon regeneration and remyelination. The protein array results suggested that the siRNAs/PLNG scaffold could increase the expression of growth factors and decrease the expression of inflammatory factors to regulate neuroinflammation in SCI and create a neural repair environment. Our results suggested that the PLNG scaffold siRNA delivery system is a potential candidate for siRNA-based SCI therapy.

New strategy of personalized tissue regeneration: when autologous platelet concentrates encounter biomaterials

Components in blood play an important role in wound healing and subsequent tissue regeneration processes. The fibrin matrix and various bioactive molecules work together to participate in this complex yet vital biological process. As a means of personalized medicine, autologous platelet concentrates have become an integral part of various tissue regeneration strategies. Here, we focus on how autologous platelet concentrates play a role in each stage of tissue healing, as well as how they work in conjunction with different types of biomaterials to participate in this process. In particular, we highlight the use of various biomaterials to protect, deliver and enhance these libraries of biomolecules, thereby overcoming the inherent disadvantages of autologous platelet concentrates and enabling them to function better in tissue regeneration.