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Research on injectable polymers (IPs) has been actively conducted in recent decades for biomedical applications. Temperature‐responsive IPs are especially effective because they can be gelled by injecting them into a living organism without external contamination. Adipose‐derived stem cells (AdSCs) can be easily harvested in a minimally invasive manner and differentiated into various cell lineages. Versatile therapeutic applications have been developed through the secretion of various cytokines from AdSCs. In this study, we prepared IP hydrogels comprising a temperature‐responsive polymer with reactive succinimide groups (tri‐PCG‐OSu), a biomacromolecule (gelatin) as a crosslinker, and Pluronic with RGDS peptide (PL‐RGDS) as a cell adhesion factor to extend the duration of the gel state and improve cell engraftment in the IP hydrogels for AdSC delivery. The combined use of gelatin and cell adhesion peptides in the polymer matrix improved the fraction of living cells encapsulated in the IP hydrogels and increased the expression levels of angiogenic factors in AdSCs cultured within them. We also presume that a certain number of cells in the IP hydrogels could be differentiated into adipocytes using the differentiation‐inducing medium. These results suggest that our temperature‐responsive IP system could be used as a cell delivery material for regenerative medicine. [ABSTRACT FROM AUTHOR]

Tissue and organ defects caused by trauma, disease, and congenital malformations present significant clinical challenges. Traditional tissue engineering (TE) requires the preparation of scaffolds before cell seeding, which is not only time-consuming but also causes poor cell infiltration and uneven distribution within the scaffold. Moreover, cells are prone to differentiation and contamination. Although 3D bioprinting and in situ TE can create scaffolds with spatially oriented cells, they still exhibit limitations in generating internal nanofiber structures. To address these challenges, we developed a hand-held in situ electrospinning device capable of constructing nanofiber scaffolds directly at sites. We further explored the effects of voltage, materials, and solvent on cell viability during the in situ cell electrospinning (IS-CE) process; completing cell encapsulation and delivery while preparing nanofibers in situ, the cell-laden nanofiber scaffolds were able to deliver highly active cells to the target sites. Additionally, IS-CE did not affect the cell stiffness and cell activity (such as proliferation, apoptosis, viability, etc.) of umbilical cord mesenchymal stem cells. RNA sequencing showed that IS-CE could alter the expression of multiple genes, enhancing cell adhesion and maintaining stem cell properties. This study achieved noncontact and highly active cell delivery, providing a technical and theoretical basis for the application of IS-CE in organ and tissue repair. [ABSTRACT FROM AUTHOR]

Nerve repair and regeneration are still challenging issues in the world, mainly due to the complex anatomic structure and limited regeneration ability of natural nerves. Tissue engineering provides a structure and function similar to nerve tissue through scaffold materials, seed cells, and active factors, which is a promising method to treat nerve injury. Gelatin methacrylate (GelMA) hydrogel is a kind of gelatin modified by methacrylamide, which possesses adjustable mechanical properties, convenient processability, and excellent biocompatibility, has been widely used in nerve tissue engineering. In this paper, the research progress of GelMA-based hydrogel in nerve repair and regeneration in recent five years is reviewed, with emphasis on the advanced manufacturing technologies of three-dimensional (3D) GelMA scaffold and the application systems that can effectively promote nerve repair and regeneration. We also evaluated the challenges and prospects of GelMA-based hydrogels in the field of nerve repair and regeneration, which is of guiding significance to the research of nerve tissue engineering. [ABSTRACT FROM AUTHOR]

Abstract Acute myocardial infarction (AMI) has been treated via injectable hydrogels and biomaterial patches invented using tissue engineering advancements over the past decade. Yet the curative potential of injectable hydrogels and stem cells is limited. Here, we propose the development of an injectable and conductive hydrogel composed of oxidised macromolecular hyaluronic acid and chitosan-grafted aniline tetramer polymeric components. In an attempt to enhance the therapeutic potential of AMI therapy, mesenchymal stem cells derived from human umbilical cord blood (HUCB-MSC) have been integrated into the formulation of a conductive hydrogel. For reliable connection to the beating hearts, the hydrogel exhibited suitable adhesive properties. Hydrogel’s potent biocompatibility was determined by in vitro investigations of cell viability and proliferation of NRCMs and H9C2 cardiomyocytes. After myocardial injection, longer HUCB-MSCs survival length, cardiac functioning, and histology in SD rat myocardium were demonstrated, greatly associated by up-regulation and downregulation of cardiac-related relative gene expressions of angiogenic factors and inflammatory factors, respectively. The injectable hydrogel that contained HUCB-MSCs substantially enhanced the therapeutic benefits, indicating a potentially beneficial therapeutic approach to AMI therapy.

Highlights This review provides a comprehensive summary associated with recent progress in the preparation and application of microgels. The characteristics and applications of microgels and microgel-based scaffolds for cell culture and delivery are elaborated with an emphasis on the advantages of these carriers in cell therapy. This review expounds on the ongoing and foreseeable applications and current limitations of microgels and their aggregate in the field of biomedical engineering. Through stimulating innovative ideas, the present review paves new avenues for expanding the application of microgels in cell delivery techniques.

Safe and accurate in situ delivery of biocompatible materials is a fundamental requirement for many biomedical applications. These include sustained and local drug release, implantation of acellular biocompatible scaffolds, and transplantation of cells and engineered tissues for functional restoration of damaged tissues and organs. The common practice today includes highly invasive operations with major risks of surgical complications including adjacent tissue damage, infections, and long healing periods. In this work, a novel non‐invasive delivery method is presented for scaffold, cells, and drug delivery deep into the body to target inner tissues. This technology is based on acousto‐sensitive materials which are polymerized by ultrasound induction through an external transducer in a rapid and local fashion without additional photoinitiators or precursors. The applicability of this technology is demonstrated for viable and functional cell delivery, for drug delivery with sustained release profiles, and for 3D printing. Moreover, the mechanical properties of the delivered scaffold can be tuned to the desired target tissue as well as controlling the drug release profile. This promising technology may shift the paradigm for local and non‐invasive material delivery approach in many clinical applications as well as a new printing method – "acousto‐printing" for 3D printing and in situ bioprinting. [ABSTRACT FROM AUTHOR]

Acute myocardial infarction (AMI) has been treated via injectable hydrogels and biomaterial patches invented using tissue engineering advancements over the past decade. Yet the curative potential of injectable hydrogels and stem cells is limited. Here, we propose the development of an injectable and conductive hydrogel composed of oxidised macromolecular hyaluronic acid and chitosan-grafted aniline tetramer polymeric components. In an attempt to enhance the therapeutic potential of AMI therapy, mesenchymal stem cells derived from human umbilical cord blood (HUCB-MSC) have been integrated into the formulation of a conductive hydrogel. For reliable connection to the beating hearts, the hydrogel exhibited suitable adhesive properties. Hydrogel's potent biocompatibility was determined by in vitro investigations of cell viability and proliferation of NRCMs and H9C2 cardiomyocytes. After myocardial injection, longer HUCB-MSCs survival length, cardiac functioning, and histology in SD rat myocardium were demonstrated, greatly associated by up-regulation and downregulation of cardiac-related relative gene expressions of angiogenic factors and inflammatory factors, respectively. The injectable hydrogel that contained HUCB-MSCs substantially enhanced the therapeutic benefits, indicating a potentially beneficial therapeutic approach to AMI therapy. [ABSTRACT FROM AUTHOR]

Highlights: This review provides a comprehensive summary associated with recent progress in the preparation and application of microgels. The characteristics and applications of microgels and microgel-based scaffolds for cell culture and delivery are elaborated with an emphasis on the advantages of these carriers in cell therapy. This review expounds on the ongoing and foreseeable applications and current limitations of microgels and their aggregate in the field of biomedical engineering. Through stimulating innovative ideas, the present review paves new avenues for expanding the application of microgels in cell delivery techniques. Microgels prepared from natural or synthetic hydrogel materials have aroused extensive attention as multifunctional cells or drug carriers, that are promising for tissue engineering and regenerative medicine. Microgels can also be aggregated into microporous scaffolds, promoting cell infiltration and proliferation for tissue repair. This review gives an overview of recent developments in the fabrication techniques and applications of microgels. A series of conventional and novel strategies including emulsification, microfluidic, lithography, electrospray, centrifugation, gas-shearing, three-dimensional bioprinting, etc. are discussed in depth. The characteristics and applications of microgels and microgel-based scaffolds for cell culture and delivery are elaborated with an emphasis on the advantages of these carriers in cell therapy. Additionally, we expound on the ongoing and foreseeable applications and current limitations of microgels and their aggregate in the field of biomedical engineering. Through stimulating innovative ideas, the present review paves new avenues for expanding the application of microgels in cell delivery techniques. [ABSTRACT FROM AUTHOR]

IntroductionNanofibrous spheres, with their injectable format and biomimetic three-dimensional topologies that emulate the complexity of natural extracellular environments, have become increasingly attractive for applications in biomedical and regenerative medicine. Our research contributes to this growing field by detailing the design and fabrication of a novel series of polylactic acid/nano-hydroxyapatite (PLA/nHA) hybrid nanofibrous spheres.MethodsThese advanced structures were created by integrating electrospinning and electrospray techniques, which allowed for precise control over the nanofibrous spheres, especially in size. We have conducted a comprehensive investigation into the nanofibrous spheres’ capacity to deliver stem cells efficiently and maintain their viability post-implantation, as well as their potential to induce osteogenic differentiation.Results and DiscussionThe results show that these nanofibrous spheres are biocompatible and injectable, effectively supporting the attachment, growth, and differentiation of bone marrow-derived mesenchymal stem cells while aiding in their targeted transportation to bone defect areas to execute their regenerative functions. The findings of this study could significantly impact the future development of biocompatible materials for a range of therapeutic applications, including bone tissue engineering and regenerative therapy.

Allogeneic tumor cell vaccines provide off‐the‐shelf convenience but lack patient specificity due to heterogeneity in tumor antigens. Here, allogeneic tumor cell corpses are converted into "zombie cells" capable of assimilating heterogeneous tumor by seizing cancer cells and spreading adjuvant infection. This causes pseudo‐oncolysis of tumors, transforming them into immunogenic targets for enhanced phagocytosis. It is shown that in postoperative tumor models, localized delivery of premade "zombie cells" through stepwise gelation in resection cavity consolidates tumor surgery. Compared to analogous vaccines lacking "seizing" or "assimilating" capability, "zombie cell" platform effectively mobilizes T cell response against residual tumors, and establishes immunological memory against tumor re‐challenge, showing less susceptibility to immune evasion. Despite using allogeneic sources, "zombie cell" platform functions as generalizable framework to produce long‐term antitumor immunity in different tumor models, showing comparable effect to autologous vaccine. Together, with the potential of off‐the‐shelf availability and personalized relevance to heterogenous tumor antigens, this study suggests an alternative strategy for timely therapy after tumor surgery. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) have displayed potential in regenerating organ function due to their anti-fibrotic, anti-inflammatory, and regenerative properties. However, there is a need for delivery systems to enhance MSC retention while maintaining their anti-fibrotic characteristics. This study investigates the feasibility of using alginate hydrogel microstrands as a cell delivery vehicle to maintain MSC viability and phenotype. To accommodate cell implantation needs, we invented a Syringe-in-Syringe approach to reproducibly fabricate microstrands in small numbers with a diameter of around 200 µm and a porous structure, which would allow for transporting nutrients to cells by diffusion. Using murine NIH 3T3 fibroblasts and primary embryonic 16 (E16) salivary mesenchyme cells as primary stromal cell models, we assessed cell viability, growth, and expression of mesenchymal and fibrotic markers in microstrands. Cell viability remained higher than 90% for both cell types. To determine cell number within the microstrands prior to in vivo implantation, we have further optimized the alamarBlue assay to measure viable cell growth in microstrands. We have shown the effect of initial cell seeding density and culture period on cell viability and growth to accommodate future stromal cell delivery and implantation. Additionally, we confirmed homeostatic phenotype maintenance for E16 mesenchyme cells in microstrands. [ABSTRACT FROM AUTHOR]

Antibody (Ab)‐based drugs have been widely used in targeted therapies and immunotherapies, leading to significant improvements in tumor therapy. However, the failure of Ab therapy due to the loss of target antigens or Ab modifications that affect its function limits its application. In this study, we expanded the application of antibodies (Abs) by constructing a fusion protein as a versatile tool for Ab‐based target cell detection, delivery, and therapy. We first constructed a SpaC Catcher (SpaCC for short) fusion protein that included the C domains of Staphylococcal protein A (SpaC) and the SpyCatcher. SpaCC conjugated with SpyTag‐X (S‐X) to form the SpaCC‐S‐X complex, which binds non‐covalently to an Ab to form the Ab‐SpaCC‐S‐X protein complex. The "X" can be a variety of small molecules such as fluoresceins, cell‐penetrating peptide TAT, Monomethyl auristatin E (MMAE), and DNA. We found that Ab‐SpaCC‐S‐FITC(−TAT) could be used for target cell detection and delivery. Besides, we synthesized the Ab‐SpaCC‐SN3‐MMAE complex by linking Ab with MMAE by SpaCC, which improved the cytotoxicity of small molecule toxins. Moreover, we constructed an Ab‐DNA complex by conjugating SpaCC with the aptamer (Ap) and found that Ab‐SpaCC‐SN3‐Ap boosted the tumor‐killing function of T‐cells by retargeting tumor cells. Thus, we developed a multifunctional tool that could be used for targeted therapies and immunotherapies, providing a cheap and convenient novel drug development strategy. [ABSTRACT FROM AUTHOR]

Immune cells have emerged as powerful regulators of regenerative as well as pathological processes. The vast majority of regenerative immunoengineering efforts have focused on macrophages; however, growing evidence suggests that other cells of both the innate and adaptive immune system are as important for successful revascularization and tissue repair. Moreover, spatiotemporal regulation of immune cells and their signaling have a significant impact on the regeneration speed and the extent of functional recovery. In this review, we summarize the contribution of different types of immune cells to the healing process and discuss ways to manipulate and control immune cells in favor of vascularization and tissue regeneration. In addition to cell delivery and cell-free therapies using extracellular vesicles, we discuss in situ strategies and engineering approaches to attract specific types of immune cells and modulate their phenotypes. This field is making advances to uncover the extraordinary potential of immune cells and their secretome in the regulation of vascularization and tissue remodeling. Understanding the principles of immunoregulation will help us design advanced immunoengineering platforms to harness their power for tissue regeneration.

Abstract Allogeneic tumor cell vaccines provide off‐the‐shelf convenience but lack patient specificity due to heterogeneity in tumor antigens. Here, allogeneic tumor cell corpses are converted into “zombie cells” capable of assimilating heterogeneous tumor by seizing cancer cells and spreading adjuvant infection. This causes pseudo‐oncolysis of tumors, transforming them into immunogenic targets for enhanced phagocytosis. It is shown that in postoperative tumor models, localized delivery of premade “zombie cells” through stepwise gelation in resection cavity consolidates tumor surgery. Compared to analogous vaccines lacking “seizing” or “assimilating” capability, “zombie cell” platform effectively mobilizes T cell response against residual tumors, and establishes immunological memory against tumor re‐challenge, showing less susceptibility to immune evasion. Despite using allogeneic sources, “zombie cell” platform functions as generalizable framework to produce long‐term antitumor immunity in different tumor models, showing comparable effect to autologous vaccine. Together, with the potential of off‐the‐shelf availability and personalized relevance to heterogenous tumor antigens, this study suggests an alternative strategy for timely therapy after tumor surgery.

Poly(lactic-glycolic acid) (PLGA) is a biocompatible bio-scaffold material, but its own hydrophobic and electrically neutral surface limits its application as a cell scaffold. Polymer materials, mimics ECM materials, and organic material have often been used as coating materials for PLGA cell scaffolds to improve the poor cell adhesion of PLGA and enhance tissue adaptation. These coating materials can be modified on the PLGA surface via simple physical or chemical methods, and coating multiple materials can simultaneously confer different functions to the PLGA scaffold; not only does this ensure stronger cell adhesion but it also modulates cell behavior and function. This approach to coating could facilitate the production of more PLGA-based cell scaffolds. This review focuses on the PLGA surface-modified materials, methods, and applications, and will provide guidance for PLGA surface modification. [ABSTRACT FROM AUTHOR]

Hydrogel microparticles (HMPs) stand out as promising entities in the realm of bone tissue regeneration, primarily due to their versatile capabilities in delivering cells and bioactive molecules/drugs. Their significance is underscored by distinct attributes such as injectability, biodegradability, high porosity, and mechanical tunability. These characteristics play a pivotal role in fostering vasculature formation, facilitating mineral deposition, and contributing to the overall regeneration of bone tissue. Fabricated through diverse techniques (batch emulsion, microfluidics, lithography, and electrohydrodynamic spraying), HMPs exhibit multifunctionality, serving as vehicles for drug and cell delivery, providing structural scaffolding, and functioning as bioinks for advanced 3D-printing applications. Distinguishing themselves from other scaffolds like bulk hydrogels, cryogels, foams, meshes, and fibers, HMPs provide a higher surface-area-to-volume ratio, promoting improved interactions with the surrounding tissues and facilitating the efficient delivery of cells and bioactive molecules. Notably, their minimally invasive injectability and modular properties, offering various designs and configurations, contribute to their attractiveness for biomedical applications. This comprehensive review aims to delve into the progressive advancements in HMPs, specifically for bone regeneration. The exploration encompasses synthesis and functionalization techniques, providing an understanding of their diverse applications, as documented in the existing literature. The overarching goal is to shed light on the advantages and potential of HMPs within the field of engineering bone tissue. [ABSTRACT FROM AUTHOR]

Titanium dioxide or aminopropylsilanol nanoparticles were shown to be effective vehicles for delivering oligodeoxyribonucleotides and deoxyribozymes to cells to affect target nucleic acids. In this paper, the proposed principle of the delivery has been implemented in relation to oligoribonucleotides (ORN), components of short interfering RNAs (siRNAs). It has been shown that the obtained ORN-containing nanocomplexes (Si~NH2·ORN) based on aminopropylsilanol nanoparticles penetrate eukaryotic cells. These nanocomplexes have been investigated as agents for suppressing the replication of influenza A virus (IAV) in the cellular system. It has been shown that the ORN strands targeted to (+)RNA and (–)RNA of the IAV 5th segment reduces the titer of the virus by 99.7% and 98.4%, respectively. Thus, oligoribonucleotides in the Si~NH2·ORN nanocomplexes effectively inhibit the replication of the influenza A virus. [ABSTRACT FROM AUTHOR]

Stem cells play critical roles in cell therapies and tissue engineering for nerve repair. However, achieving effective delivery of high cell density remains a challenge. Here, a novel cell delivery platform termed the hyper expansion scaffold (HES) is developed to enable high cell loading. HES facilitated self‐promoted and efficient cell absorption via a dual driving force model. In vitro tests revealed that the HES rapidly expanded 80‐fold in size upon absorbing 2.6 million human amniotic epithelial stem cells (hAESCs) within 2 min, representing over a 400% increase in loading capacity versus controls. This enhanced uptake benefited from macroscopic swelling forces as well as microscale capillary action. In spinal cord injury (SCI) rats, HES–hAESCs promoted functional recovery and axonal projection by reducing neuroinflammation and improving the neurotrophic microenvironment surrounding the lesions. In summary, the dual driving forces model provides a new rationale for engineering hydrogel scaffolds to facilitate self‐promoted cell absorption. The HES platform demonstrates great potential as a powerful and efficient vehicle for delivering high densities of hAESCs to promote clinical treatment and repair of SCI. [ABSTRACT FROM AUTHOR]

Simple Summary: Over the years, diverse therapeutic protocols have been employed for cardiac tissue engineering (CTE) and improvement of the heart functions. Among them are stem cells which possess a high tissue-regeneration potential. However, the optimum delivery protocol with effective cell retention and homing at the target site is still challenging. Hence, a wide range of natural and synthetic biomaterials have been utilized as cell delivery cargoes to address these limitations. Natural decellularized biomaterials could provide successful biocompatible, biodegradable, elastic, and strong platforms that avoid the drawbacks of synthetic ones. Hence, in the present study, we have prepared a decellularized porcine pericardium (DPP) patch to provide successful tailored cell discharge, retention, and homing at the site of the myocardial infarction (MI) with an outstanding ability to restore the damaged heart activity. Moreover, we have provided for the first time a novel echocardiographic-derived imaging modality called the intraventricular pressure gradient (IVPG) to evaluate the process. The IVPG provides a precise, non-invasive, and facile tool to assess cardiac functions. This speeds up the accumulation of knowledge and opens new avenues to objectively evaluate diagnosis and treatment, which encourages the implementation of such a cutting-edge strategy in clinical practices in the near future. Myocardial infarction (MI) is a serious cardiovascular disease as the leading cause of death globally. Hence, reconstruction of the cardiac tissue comes at the forefront of strategies adopted to restore heart functions following MI. In this investigation, we studied the capacity of rat adipose-derived mesenchymal stem cells (r-AdMSCs) and decellularized porcine pericardium (DPP) to restore heart functions in MI animals. MI was induced in four different groups, three of which were treated either using DPP (MI-DPP group), stem cells (MI-SC group), or both (MI-SC/DPP group). Cardiac functions of these groups and the Sham group were evaluated using echocardiography, the intraventricular pressure gradient (IVPG) on weeks 2 and 4, and intraventricular hemodynamics on week 4. On day 31, the animals were euthanized for histological analysis. Echocardiographic, IVPG and hemodynamic findings indicated that the three treatment strategies shared effectively in the regeneration process. However, the MI-SC/DPP group had a unique synergistic ability to restore heart functions superior to the other treatment protocols. Histology showed that the MI-SC/DPP group presented the lowest (p < 0.05) degeneration score and fibrosis % compared to the other groups. Conclusively, stem cell-seeded DPP is a promising platform for the delivery of stem cells and restoration of heart functions post-MI. [ABSTRACT FROM AUTHOR]

Abstract Stem cells play critical roles in cell therapies and tissue engineering for nerve repair. However, achieving effective delivery of high cell density remains a challenge. Here, a novel cell delivery platform termed the hyper expansion scaffold (HES) is developed to enable high cell loading. HES facilitated self‐promoted and efficient cell absorption via a dual driving force model. In vitro tests revealed that the HES rapidly expanded 80‐fold in size upon absorbing 2.6 million human amniotic epithelial stem cells (hAESCs) within 2 min, representing over a 400% increase in loading capacity versus controls. This enhanced uptake benefited from macroscopic swelling forces as well as microscale capillary action. In spinal cord injury (SCI) rats, HES–hAESCs promoted functional recovery and axonal projection by reducing neuroinflammation and improving the neurotrophic microenvironment surrounding the lesions. In summary, the dual driving forces model provides a new rationale for engineering hydrogel scaffolds to facilitate self‐promoted cell absorption. The HES platform demonstrates great potential as a powerful and efficient vehicle for delivering high densities of hAESCs to promote clinical treatment and repair of SCI.

Degenerative intervertebral disc disease is a common source of chronic pain and reduced quality of life in people over the age of 40. While degeneration occurs throughout the disc, it most often initiates in the nucleus pulposus (NP). Minimally invasive delivery of NP cells within hydrogels that can restore and maintain the disc height while regenerating the damaged NP tissue is a promising treatment strategy for this condition. Towards this goal, a biohybrid ABA dimethacrylate triblock copolymer was synthesized, possessing a lower critical solution temperature below 37 °C and which contained as its central block an MMP-degradable peptide flanked by poly(trimethylene carbonate) blocks bearing pendant oligoethylene glycol groups. This triblock prepolymer was used to form macroporous NP cell-laden hydrogels via redox initiated (ammonium persulfate/sodium bisulfite) crosslinking, with or without the inclusion of thiolated chondroitin sulfate. The resulting macroporous hydrogels had water and mechanical properties similar to those of human NP tissue and were mechanically resilient. The hydrogels supported NP cell attachment and growth over 28 days in hypoxic culture. In hydrogels prepared with the triblock copolymer but without the chondroitin sulfate the NP cells were distributed homogeneously throughout in clusters and deposited collagen type II and sulfated glycosaminoglycans but not collagen type I. This hydrogel formulation warrants further investigation as a cell delivery vehicle to regenerate degenerated NP tissue. The intervertebral disc between the vertebral bones of the spine consists of three regions: a gel-like central nucleus pulposus (NP) within the annulus fibrosis, and bony endplates. Degeneration of the intervertebral disc is a source of chronic pain in the elderly and most commonly initiates in the NP. Replacement of degenerated NP tissue with a NP cell-laden hydrogel is a promising treatment strategy. Herein we demonstrate that a crosslinkable polymer with a lower critical solution temperature below 37 °C can be used to form macroporous hydrogels for this purpose. The hydrogels are capable of supporting NP cells, which deposit collagen II and sulfated glycosaminoglycans, while also possessing mechanical properties matching those of human NP tissue. [Display omitted] [ABSTRACT FROM AUTHOR]

The strategies for modulating the local inflammatory microenvironment to inhibit intervertebral disc degeneration (IVDD) have garnered significant interest in recent years. In this study, we developed a "self-contained" injectable hydrogel capable of storing Mg2+ while carrying nucleus pulposus (NP) cells, with the aim of inhibiting IVDD through immunoregulation. The hydrogel consists of sodium alginate (SA), poly(N-isopropylacrylamide) (PNIPAAm), silicate ceramics (SC), and NP cells. When injected into the NP site, PNIPAAm gelates instantly under body temperature, forming an interpenetrating network (IPN) hydrogel with SA. Ca2+ released from the SC can crosslink the SA in situ , forming a SA/PNIPAAm hydrogel with an interpenetrating network (IPN) encapsulating the NP cells. Moreover, inside the hydrogel, Mg2+ released from SC are effectively encapsulated and maintained at a desirable concentration. These Mg2+ facilitates the local cell matrix synthesis and promotes immunomodulation (upregulating M2 / downregulating M1 macrophage polarization), thus inhibiting the IVDD progression. The proposed hydrogel has biocompatibility and is shown to enhance the expression of collagen II (COL II) and aggrecan. The potential of the injectable hydrogel in IVD repair has also been successfully demonstrated by in vivo studies. • A unique injectable hydrogel consisting of sodium alginate (SA), poly(N-isopropylacrylamide) (PNIPAAm), silicate ceramics (SC) and nucleus pulposus cells, has been created for intervertebral disc repair applications. • This is the first "self-contained" cell delivery system capable of releasing and subsequently storing Mg2+ in the hydrogel reservoir for localized treatment. • The role of Mg2+ in regulating the macrophage polarity transformation (from pro-inflammatory M1 to anti-inflammatory M2 phenotype) has been unveiled in the context of intervertebral disc repair. [Display omitted] [ABSTRACT FROM AUTHOR]

Cell-based therapeutics are novel therapeutic strategies that can potentially treat many presently incurable diseases through novel mechanisms of action. Cell therapies may benefit from the ease, safety, and efficacy of administering therapeutic cells. Despite considerable recent technological and biological advances, several barriers remain to the clinical translation and commercialization of cell-based therapies, including low patient compliance, personal handling inconvenience, poor biosafety, and limited biocompatibility. Microneedles (MNs) are emerging as a promising biomedical device option for improved cell delivery with little invasion, pain-free administration, and simplicity of disposal. MNs have shown considerable promise in treating a wide range of diseases and present the potential to improve cell-based therapies. In this review, we first summarized the latest advances in the various types of MNs developed for cell delivery and cell sampling. Emphasis was given to the design and fabrication of various types of MNs based on their structures and materials. Then we focus on the recent biomedical applications status of MNs-mediated cell delivery and sampling, including tissue repair (wound healing, heart repair, and endothelial repair), cancer treatment, diabetes therapy, cell sampling, and other applications. Finally, the current status of clinical application, potential perspectives, and the challenges for clinical translation are also highlighted. [Display omitted] [ABSTRACT FROM AUTHOR]

Neurological injuries have poor prognoses with serious clinical sequelae. Stem cell transplantation enhances neural repair but is hampered by low graft survival (ca. 80%) and marker expression/proliferative potential of hydrogel-sprayed astrocytes was retained. Combining a cell spray format with polymer encapsulation technologies could form the basis of a non-invasive graft delivery method, offering potential advantages over current cell delivery approaches. [ABSTRACT FROM AUTHOR]

Complete skin reconstruction is a hierarchical, physiological assembly process involving healing of the epidermis, dermis, vasculature, nerves, and cutaneous appendages. To date, few works have reported complete skin regeneration, particularly lacking vascular structures and hair follicles after full skin defects. In this study, a hydrogel derived from the skin secretion of Andrias davidianus (SSAD) that features adhesiveness was used as a bioactive scaffold to load micronized amnion (MA). The SSAD hydrogel was found to promote the migration and proliferation of amnion stem cells and human keratinocytes, as well as inhibit their apoptosis in vitro. In a rat full‐skin defect model, the regeneration of skin appendages was observed at the wound area, achieving scarless healing. Transcriptome analyses further validated that SSAD could positively regulate cell migration, proliferation, and differentiation. These functions might be attributed to the abundant growth factors present in the SSAD. Synergized by the delivery of MA, SSAD loaded with the MA could achieve a significantly better skin regeneration effect than SSAD or MA used alone, providing a simple yet highly effective means to obtain complete, scarless skin regeneration, suggesting favorable potential for clinical translation. [ABSTRACT FROM AUTHOR]

Granular hydrogels are a promising biomaterial for a wide range of biomedical applications, including tissue regeneration, drug/cell delivery, and 3D printing. These granular hydrogels are created by assembling microgels through the jamming process. However, current methods for interconnecting the microgels often limit their use due to the reliance on postprocessing for crosslinking through photoinitiated reactions or enzymatic catalysis. To address this limitation, we incorporated a thiol‐functionalized thermo‐responsive polymer into oxidized hyaluronic acid microgel assemblies. The rapid exchange rate of thiol‐aldehyde dynamic covalent bonds allows the microgel assembly to be shear‐thinning and self‐healing, with the phase transition behavior of the thermo‐responsive polymer serving as secondary crosslinking to stabilize the granular hydrogels network at body temperature. This two‐stage crosslinking system provides excellent injectability and shape stability, while maintaining mechanical integrity. In addition, the aldehyde groups of the microgels act as covalent binding sites for sustained drug release. These granular hydrogels can be used as scaffolds for cell delivery and encapsulation, and can be 3D printed without the need for post‐printing processing to maintain mechanical stability. Overall, our work introduces thermo‐responsive granular hydrogels with promising potential for various biomedical applications. [ABSTRACT FROM AUTHOR]

Cellular therapies for burn wound healing, including the administration of mesenchymal stem or stromal cells (MSCs), have shown promising results. This review aims to provide an overview of the current administration methods in preclinical and clinical studies of bone-marrow-, adipose-tissue-, and umbilical-cord-derived MSCs for treating burn wounds. Relevant studies were identified through a literature search in PubMed and Embase and subjected to inclusion and exclusion criteria for eligibility. Additional relevant studies were identified through a manual search of reference lists. A total of sixty-nine studies were included in this review. Of the included studies, only five had clinical data from patients, one was a prospective case–control, three were case reports, and one was a case series. Administration methods used were local injection (41% in preclinical and 40% in clinical studies), cell-seeded scaffolds (35% and 20%), topical application (17% and 60%), and systemic injection (1% and 0%). There was great heterogeneity between the studies regarding experimental models, administration methods, and cell dosages. Local injection was the most common administration method in animal studies, while topical application was used in most clinical reports. The best delivery method of MSCs in burn wounds is yet to be identified. Although the potential of MSC treatment for burn wounds is promising, future research should focus on examining the effect and scalability of such therapy in clinical trials.

Abstract Complete skin reconstruction is a hierarchical, physiological assembly process involving healing of the epidermis, dermis, vasculature, nerves, and cutaneous appendages. To date, few works have reported complete skin regeneration, particularly lacking vascular structures and hair follicles after full skin defects. In this study, a hydrogel derived from the skin secretion of Andrias davidianus (SSAD) that features adhesiveness was used as a bioactive scaffold to load micronized amnion (MA). The SSAD hydrogel was found to promote the migration and proliferation of amnion stem cells and human keratinocytes, as well as inhibit their apoptosis in vitro. In a rat full‐skin defect model, the regeneration of skin appendages was observed at the wound area, achieving scarless healing. Transcriptome analyses further validated that SSAD could positively regulate cell migration, proliferation, and differentiation. These functions might be attributed to the abundant growth factors present in the SSAD. Synergized by the delivery of MA, SSAD loaded with the MA could achieve a significantly better skin regeneration effect than SSAD or MA used alone, providing a simple yet highly effective means to obtain complete, scarless skin regeneration, suggesting favorable potential for clinical translation.

Cell transplants in therapeutic studies do not preserve their long-term function inside the donor body. In mesenchymal stem cell (MSC) transplants, transplanted cells disperse through the body and are prone to degradation by immune cells after the transplant process. Various strategies, such as usage of the immunosuppressive drugs to eliminate allograft rejection, are designed to increase the efficiency of cell therapy. Another strategy is the construction of biomimetic encapsulates using polymeric materials, which isolate stem cells and protect them from environmental effects. In this study, fibroblasts (L929) and MSCs were investigated for their improved viability and functionality once encapsulated inside the alginate microbeads under in vitro conditions for up to 12 days of incubation. Thus, uniform and injectable (<200 µm) cell-loaded microbeads were constructed by the electrostatically assisted spraying technique. Results showed that both L929 and MSCs cells continue their metabolic activity inside the microbeads during the incubation periods. Glucose consumption and lactic acid production levels of both cell lines were consistently observed. The released cell number on day 12 was found to be increased compared to day 0. Protein expression levels of both groups increased every day with the expected doubling rate. Hence, this strategy with a simple yet clever design to encapsulate either MSCs or L929 cells might outstand as a potential cell delivery platform for cell therapy-based tissue engineering. [ABSTRACT FROM AUTHOR]

Gene delivery has emerged as a promising alternative to conventional treatment approaches, allowing for the manipulation of gene expression through gene insertion, deletion, or alteration. However, the susceptibility of gene delivery components to degradation and challenges associated with cell penetration necessitate the use of delivery vehicles for effective functional gene delivery. Nanostructured vehicles, such as iron oxide nanoparticles (IONs) including magnetite nanoparticles (MNPs), have demonstrated significant potential for gene delivery applications due to their chemical versatility, biocompatibility, and strong magnetization. In this study, we developed an ION-based delivery vehicle capable of releasing linearized nucleic acids (tDNA) under reducing conditions in various cell cultures. As a proof of concept, we immobilized a CRISPR activation (CRISPRa) sequence to overexpress the pink1 gene on MNPs functionalized with polyethylene glycol (PEG), 3-[(2-aminoethyl)dithio]propionic acid (AEDP), and a translocating protein (OmpA). The nucleic sequence (tDNA) was modified to include a terminal thiol group and was conjugated to AEDP's terminal thiol via a disulfide exchange reaction. Leveraging the natural sensitivity of the disulfide bridge, the cargo was released under reducing conditions. Physicochemical characterizations, including thermogravimetric analysis (TGA) and Fourier-transform infrared (FTIR) spectroscopy, confirmed the correct synthesis and functionalization of the MNP-based delivery carriers. The developed nanocarriers exhibited remarkable biocompatibility, as demonstrated by the hemocompatibility, platelet aggregation, and cytocompatibility assays using primary human astrocytes, rodent astrocytes, and human fibroblast cells. Furthermore, the nanocarriers enabled efficient cargo penetration, uptake, and endosomal escape, with minimal nucleofection. A preliminary functionality test using RT-qPCR revealed that the vehicle facilitated the timely release of CRISPRa vectors, resulting in a remarkable 130-fold overexpression of pink1. We demonstrate the potential of the developed ION-based nanocarrier as a versatile and promising gene delivery vehicle with potential applications in gene therapy. The developed nanocarrier is capable of delivering any nucleic sequence (up to 8.2 kb) once it is thiolated using the methodology explained in this study. To our knowledge, this represents the first MNP-based nanocarrier capable of delivering nucleic sequences under specific reducing conditions while preserving functionality. [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) have displayed potential in regenerating organ function due to their anti-fibrotic, anti-inflammatory, and regenerative properties. However, there is a need for delivery systems to enhance MSC retention while maintaining their anti-fibrotic characteristics. This study investigates the feasibility of using alginate hydrogel microstrands as a cell delivery vehicle to maintain MSC viability and phenotype. To accommodate cell implantation needs, we invented a Syringe-in-Syringe approach to reproducibly fabricate microstrands in small numbers with a diameter of around 200 µm and a porous structure, which would allow for transporting nutrients to cells by diffusion. Using murine NIH 3T3 fibroblasts and primary embryonic 16 (E16) salivary mesenchyme cells as primary stromal cell models, we assessed cell viability, growth, and expression of mesenchymal and fibrotic markers in microstrands. Cell viability remained higher than 90% for both cell types. To determine cell number within the microstrands prior to in vivo implantation, we have further optimized the alamarBlue assay to measure viable cell growth in microstrands. We have shown the effect of initial cell seeding density and culture period on cell viability and growth to accommodate future stromal cell delivery and implantation. Additionally, we confirmed homeostatic phenotype maintenance for E16 mesenchyme cells in microstrands.

This work aims to engineer a new stable injectable Mn-based methacrylated gellan gum (Mn/GG-MA) hydrogel for real-time monitored cell delivery into the central nervous system. To enable the hydrogel visualization under Magnetic Resonance Imaging (MRI), GG-MA solutions were supplemented with paramagnetic Mn2+ ions before its ionic crosslink with artificial cerebrospinal fluid (aCSF). The resulting formulations were stable, detectable by T1-weighted MRI scans and also injectable. Cell-laden hydrogels were prepared using the Mn/GG-MA formulations, extruded into aCSF for crosslink, and after 7 days of culture, the encapsulated human adipose-derived stem cells remained viable, as assessed by Live/Dead assay. In vivo tests, using double mutant MBPshi/shi/rag2 immunocompromised mice, showed that the injection of Mn/GG-MA solutions resulted in a continuous and traceable hydrogel, visible on MRI scans. Summing up, the developed formulations are suitable for both non-invasive cell delivery techniques and image-guided neurointerventions, paving the way for new therapeutic procedures. [ABSTRACT FROM AUTHOR]

Marine organisms provide novel and broad sources for the preparations and applications of biomaterials. Since the urgent requirement of bio‐hydrogels to mimic tissue extracellular matrix (ECM), the natural biomacromolecule hydrogels derived from marine sources have received increasing attention. Benefiting from their outstanding bioactivity and biocompatibility, many attempts have been made to reconstruct ECM components by applying marine‐derived natural hydrogels. Moreover, marine hydrogels have been successfully applied in biomedicine by means of microfluidics, electrospray, and bioprinting. In this review, the classification and characteristics of marine‐derived hydrogels are summarized. In particular, their role in the development of biomaterials is also introduced. Then, the recent advances in bio‐fabrication strategies for various hydrogel materials are focused upon. Besides, the influences of hydrogel types on their functions in biomedical applications are discussed in depth. Finally, critical reflections on the limitations and future development of marine‐derived hydrogels are presented. [ABSTRACT FROM AUTHOR]

Purpose: In current intraoperative MRI (IMRI) methods, an iterative approach is used to aim trajectory guides at intracerebral targets: image MR‐visible features, determine current aim by fitting model to image, manipulate device, repeat. Infrequent updates are produced by such methods, compared to rapid optically tracked stereotaxy used in the operating room. Our goal was to develop a real‐time interactive IMRI method for aiming. Methods: The current trajectory was computed from two points along the guide's central axis, rather than by imaging the entire device. These points were determined by correlating one‐dimensional spokes from a radial sequence with the known cross‐sectional projection of the guide. The real‐time platform RTHawk was utilized to control MR sequences and data acquisition. On‐screen updates were viewed by the operator while simultaneously manipulating the guide to align it with the planned trajectory. Accuracy was quantitated in a phantom, and in vivo validation was demonstrated in nonhuman primates undergoing preclinical gene (n=5$$ n=5 $$) and cell (n=4$$ n=4 $$) delivery surgeries. Results: Updates were produced at 5 Hz In 10 phantom experiments at a depth of 48 mm, the cannula tip was placed with radial error of (min, mean, max) = (0.16, 0.29, 0.68) mm. Successful in vivo delivery of payloads to all 14 targets was demonstrated across nine surgeries with depths of (min, mean, max) = (33.3, 37.9, 42.5) mm. Conclusion: A real‐time interactive update rate was achieved, reducing operator fatigue without compromising accuracy. Qualitative interpretation of images during aiming was rendered unnecessary by objectively computing device alignment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Temperature-responsive microparticle swimmers for cell manipulation. • Bio-friendly surface assembly with morphology induction and temperature cycling. • Temperature sensitivity enables controlled gelatin layer manipulation and cell interaction. • Creation of time-specific, shape-specific, and patterned heterotypic cell co-culture models.. Developing biocompatible and flexible cell manipulation tools is crucial for effective cell delivery in tissue engineering. Herein, thermo-responsive microparticle swimmers, composed of an alginate core and a rough gelatin surface, are developed as a tool for remote cell manipulation and the construction of patterned cell models. The microparticles are fabricated using a novel bio-friendly surface assembly strategy, which leverages morphology-induced gelatin adsorption combined with temperature-cycling crosslinking to deposit multiple gelatin layers onto microfluidic-derived rough microparticles. Gelatin molecules can adsorb onto the rough surface at 25 °C and become cross-linked at 4 °C to form a stable coating layer while preserving the coarse morphology for additional assembly cycles. The gelatin layers remain intact at room temperature for cell loading and transport, but rapidly dissipate at 37 °C, enabling cell release. Moreover, complex manipulations of living cell populations, such as remote tweezing, can be achieved by the introduction of magneto-responsive moieties. These versatile microparticles provide an efficient tool for the in vitro construction of flexible and dynamic patterned cell models, with promising applications in tissue engineering, drug screening, and organoid development. [ABSTRACT FROM AUTHOR]

Myocardial infarction (MI) is a serious cardiovascular disease as the leading cause of death globally. Hence, reconstruction of the cardiac tissue comes at the forefront of strategies adopted to restore heart functions following MI. In this investigation, we studied the capacity of rat adipose-derived mesenchymal stem cells (r-AdMSCs) and decellularized porcine pericardium (DPP) to restore heart functions in MI animals. MI was induced in four different groups, three of which were treated either using DPP (MI-DPP group), stem cells (MI-SC group), or both (MI-SC/DPP group). Cardiac functions of these groups and the Sham group were evaluated using echocardiography, the intraventricular pressure gradient (IVPG) on weeks 2 and 4, and intraventricular hemodynamics on week 4. On day 31, the animals were euthanized for histological analysis. Echocardiographic, IVPG and hemodynamic findings indicated that the three treatment strategies shared effectively in the regeneration process. However, the MI-SC/DPP group had a unique synergistic ability to restore heart functions superior to the other treatment protocols. Histology showed that the MI-SC/DPP group presented the lowest (p < 0.05) degeneration score and fibrosis % compared to the other groups. Conclusively, stem cell-seeded DPP is a promising platform for the delivery of stem cells and restoration of heart functions post-MI.

Abstract Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system. This disorder may cause progressive and permanent impairment, placing significant physical and psychological strain on sufferers. Each progress in MS therapy marks a significant advancement in neurological research. Hydrogels can serve as a scaffold with high water content, high expansibility, and biocompatibility to improve MS cell proliferation in vitro and therapeutic drug delivery to cells in vivo. Hydrogels may also be utilized as biosensors to detect MS-related proteins. Recent research has employed hydrogels as an adjuvant imaging agent in immunohistochemistry assays. Following an overview of the development and use of hydrogels in MS diagnostic and therapy, this review discussed hydrogel’s advantages and future opportunities in the diagnosis and treatment of MS. Graphical abstract

Numerous processing techniques aim to impart interconnected, porous structures within regenerative medicine materials to support cell delivery and direct tissue growth. Many of these techniques lack predictable control of scaffold architecture, and rapid prototyping methods are often limited by time-consuming, layer-by-layer fabrication of micro-features. Bicontinuous interfacially jammed emulsion gels (bijels) offer a robust, self-assembly-based platform for synthesizing a new class of morphologically unique cell delivery biomaterials. Bijels form via kinetic arrest of temperature-driven spinodal decomposition in partially miscible binary liquid systems. These non-equilibrium soft materials are comprised of co-continuous, fully percolating, non-constricting liquid domains separated by a nanoparticle monolayer. Through the selective introduction of biocompatible precursors, hydrogel scaffolds displaying the morphological characteristics of the parent bijel can be formed. We report using bijel templating to generate structurally unique, fibrin-loaded polyethylene glycol hydrogel composites. Demonstration of composite bijel-templated hydrogels (CBiTHs) as a new cell delivery system was carried out in vitro using fluorescence-based tracking of cells delivered to previously acellular fibrin gels. Imaging analysis confirmed repeatable delivery of normal human dermal fibroblasts to acellular fibrin gels.

Mesenchymal stem cells (MSC) are currently being investigated for their therapeutic applications in a wide range of diseases. Although many studies examined peripheral venous administration of MSC, few have investigated the detailed intravenous administration procedures of MSC from their preparation until they enter the body. The current study therefore aimed to explore the most efficient infusion procedure for MSC delivery by preparing and infusing them under various conditions. Canine adipose-derived mesenchymal stem cells (cADSC) were infused using different infusion apparatuses, suspension solutions, allogenic serum supplementation, infusion time and rates, and cell densities, respectively. Live and dead cell counts were then assessed by manual measurements and flow cytometry. Efficiency of live- and dead-cell infusion and cell viability were calculated from the measured cell counts and compared under each condition. Efficiency of live-cell infusion differed significantly according to the infusion apparatus, infusion rate, and combination of cell density and serum supplementation. Cell viability after infusion differed significantly between the infusion apparatuses. The optimal infusion procedure resulting in the highest cell delivery and viability involved suspending cADSC in normal saline supplemented with 5% allogenic serum at a density of 5 × 105 cells/mL, and infusing them using an automatic infusion device for 15 min. This procedure is therefore recommended as the standard procedure for the intravenous administration of ADSC in terms of cell-delivery efficiency. [ABSTRACT FROM AUTHOR]

In this study, we present an in situ microfluidic system to precisely control highly porous polycaprolactone microspheres as tissue templates for tissue engineering. The porosity of the microspheres was controlled by adjusting the flow rates of the polymer phase and the pore-generating material phase in the dispersed phase. The microfluidic flow-focusing technique was adopted to manufacture porous microspheres using a relatively highly viscous polymer solution, and the device was fabricated by conventional photolithography and PDMS casting. The fabricated in situ microfluidic system was used to precisely control the pore size of monodispersed polycaprolactone microspheres. The porous microspheres with controlled pore sizes were evaluated by culturing HDF cells on the surface of porous microspheres and injection into the subcutaneous tissue of rats. We found that the increased pore size of the microspheres improved the initial proliferation rate of HDF cells after seeding and relieved the inflammatory response after the implantation of porous microspheres in the subcutaneous tissue of rats. [ABSTRACT FROM AUTHOR]

Albumin is a natural biomaterial that is abundantly available in blood and body fluids. It is clinically used as a plasma expander, thereby increasing the plasma thiol concentration due to its cysteine residues. Albumin is a regulator of intervascular oncotic pressure, serves as an anti-inflammatory modulator, and it has a buffering role due to its histidine imidazole residues. Because of its unique biological and physical properties, albumin has also emerged as a suitable biomaterial for coating implantable devices, for cell and drug delivery, and as a scaffold for tissue engineering and regenerative medicine. As a biomaterial, albumin can be used as surface-modifying film or processed either as cross-linked protein gels or as electrospun fibers. Herein we have discussed how albumin protein can be utilized in regenerative medicine as a hydrogel and as a fibrous mat for a diverse role in successfully delivering drugs, genes, and cells to targeted tissues and organs. The review of prior studies indicated that albumin is a tunable biomaterial from which different types of scaffolds with mechanical properties adjustable for various biomedical applications can be fabricated. Based on the progress made to date, we concluded that albumin-based device coatings, delivery of drugs, genes, and cells are promising strategies in regenerative and personalized medicine. [ABSTRACT FROM AUTHOR]

Cell-based delivery holds great promise for advancing cell therapy, but it often faces challenges such as low cell survival rates and immunological rejection during cell injection and circulation. In this study, we develop an alternative approach aimed at engineering cell membranes to produce encapsulated individual mammalian (EIM) cells. The encapsulation shell was formed by catalyzing the reaction of H 2 O 2 with hyaluronic acid-dopamine (HA-DA) on the cell surface using horseradish peroxidase (HRP) enzymes. This protective shell not only protects live mammalian cells from physical stress but also from biological assaults. The individual cell encapsulation system enables the loading of cells with chemotherapy drugs, enhancing their targeting ability towards tumor sites and resulting in over 5.1-fold cell enrichment at metastatic tumors, thereby improving tumor-killing efficacy and reducing metastasis. Overall, the individual cell encapsulation system demonstrates potential for targeted drug delivery to the lungs in the treatment of lung cancer by reducing side effects and enhancing treatment outcomes., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Injectable porous microspheres represent a promising therapeutic platform for cell delivery, drug delivery, and tissue regeneration. Yet, the engineering of silk fibroin microspheres with a highly interconnected porous structure remains an unsolved challenge. In this study, a simple and efficient method is developed that does not require the use of organic solvents to prepare silk fibroin microspheres with a predictable structure. Through extensive screening, the addition of glucose is found to direct the formation of a highly interconnected porous structure from the interior to the surface of silk fibroin microspheres. Compared to silk fibroin microspheres (SF microspheres) produced through a combination of electro-spray, cryopreservation, and freeze drying, silk fibroin-glucose microspheres (SF-Glu microspheres) demonstrates enhanced capabilities in promoting cell adhesion and proliferation in vitro. Both SF-Glu and SF microspheres exhibit the capacity to maintain the sustained release kinetics of the loaded model drug. Furthermore, SF-Glu microspheres facilitate the recruitment of endogenous cells, capillary migration, and macrophage phenotype switch following subcutaneous injection in the rats. This study opens a new avenue for the construction of porous silk fibroin microspheres, which could lead to a broader range of applications in regenerative medicine., (© 2024 Wiley‐VCH GmbH.)