Boar sperm quality is a key intrinsic factor of reproductive success, and its optimization is crucial for improving pig production efficiency. Here, this study investigated the effect of non-thermal dielectric barrier discharge (DBD) plasma on boar sperm quality and the underlying regulatory mechanism. Results showed that optimized DBD plasma improved boar sperm viability and motility, adenosine triphosphate level, mitochondrial membrane potential, and mitochondrial respiratory chain enzyme activity, while reducing the opening degree of mitochondrial permeability transition pore. Transcriptome sequencing revealed significant changes in sperm mitophagy-related genes after DBD plasma treatment. Correspondingly, mitophagy-related proteins including Forkhead box O3 (FOXO3), PTEN induced kinase 1 (PINK1), Parkin, BCL2 interacting protein 3 (BNIP3), and LC3 II/LC3 I ratio exhibits increased at protein levels, while the protein levels of P62 and TOM20 were decreased in DBD plasma-treated spermatozoa. Mitophagy inhibitor Mdivi-1 decreased sperm mitophagy level, mitochondrial function and sperm quality, but these effects were rescued by DBD plasma. Moreover, DBD plasma increased the binding interaction of FOXO3-PINK1 and PINK1-Parkin. Silencing FOXO3, PINK1, and Parkin by using siRNAs inhibited mitophagy level, mitochondrial function, and sperm quality, but these effects were alleviated by DBD plasma. These findings illustrated appropriate DBD plasma enhanced mitochondrial function by activating FOXO3-PINK1/Parkin-mediated mitophagy, leading to improved boar sperm quality without disrupting sperm DNA integrity and acrosome integrity. Therefore, non-thermal plasma technology provides a novel strategy to enhance sperm quality through the regulation of targeted mitophagy, offering promising potential for its application in livestock reproduction.

Neurodegenerative diseases such as Huntington's Disease (HD) have a significant impact on healthcare accessibility and costs. A fatal genetic condition, characterized by the progressive loss of striatal neurons, HD is hindered by the lack of endogenous repair in the adult brain. Recent efforts toward protecting neural circuits through neurotrophic support using brain-derived neurotrophic factor (BDNF) have been suboptimal due to the protein's short half-life and limited diffusion. Addressing this, adeno-associated viral vectors (AAV) can be employed as a delivery tool to spatially transduce cells, enabling the localised production of BDNF with consequential neuron protection and/or plasticity, yet present their own constraints. To overcome these known challenges of AAV gene delivery, an injectable, physiologically stable hydrogel-mimic of the brain's extracellular matrix was fabricated to encapsulate the AAVs. This smart system both shielded and constrained the AAV; optimising transfection and therefore elevated and sustained BDNF presentation at the target site. Here, we achieved high neuroprotection using AAVDJ-BDNF delivered through a hydrogel formed via self-assembling peptide nanoscaffolds. These findings support the notion that the spatiotemporal release of BDNF to striatal neurons, facilitated by engineered biomaterial delivery systems, demonstrates tremendous promise by enhancing the efficacy of gene therapy targeted at slowing neurodegenerative disease progression.

Spinal cord injury (SCI) presents a therapeutic challenge owing to its highly dynamic pathological microenvironment, which evolves from acute inflammatory damage to chronic regenerative insufficiency. However, most biomaterial-based drug delivery systems are inherently static and fail to meet these temporally distinct therapeutic demands. Here, we present a spatiotemporally programmable bilayer hydrogel that synchronizes therapeutic delivery with the pathological progression of SCI. The outer gelatin methacryloyl (GelMA) layer is engineered to undergo rapid degradation in response to the acute upregulation of matrix metalloproteinase-2 (MMP-2), enabling the release of an antioxidant agent to attenuate oxidative stress and reprogram macrophages toward a pro-regenerative M2 phenotype. As the injury microenvironment shifts to repair phase, the inner layer becomes functionally dominant. Composed of hyaluronic acid methacrylate–polydopamine (HAMA–PDA), this layer serves as a biocompatible, photothermally responsive scaffold that enables near-infrared (NIR) light–triggered, on-demand basic fibroblast growth factor (bFGF) release to promote neuronal differentiation and axonal regeneration. Notably, the integration of enzyme-initiated immunomodulation with externally controlled regenerative stimulation markedly enhances functional recovery in a mouse SCI model. Collectively, this work establishes a pharmaco–physical biomaterial paradigm for spatiotemporal regulation of the injury microenvironment, offering a versatile strategy for neural regeneration.

Tendon injuries are prone to adhesions after repair, which in turn lead to limb dysfunction, which remains a major challenge in clinical treatment. Current research suggests that tendon injuries are affected by the accumulation of reactive oxygen species (ROS), inflammatory responses, and type III collagen deposition. These factors lead to an imbalance between extrinsic and intrinsic tendon healing and are the main reasons for the occurrence of peritendinous adhesions. In this study, we constructed a carrier using a polyvinyl alcohol/polyethylene glycol (PVA/PEG) dual network hydrogel and loaded it with zeolite imidazolium ester framework-8@CeO2 nano-enzymes (ZIF-8@CeO2) to form a nano-enzyme-functionalized hydrogel (PVA/PEG/ZIF-8@CeO2) therapeutic system. The surface of PVA/PEG/ZIF-8@CeO2 is rich in hydrophilic hydroxyl groups that form hydrogen bonds with water molecules, creating a hydrated layer that inhibits fibrin adsorption and fibroblast adhesion, reduces the impact of exogenous healing, and reduces the formation of adhesions. Similarly, the loaded ZIF-8@CeO2 has catalase (CAT) and superoxide dismutase (SOD) activities, which can effectively remove the excessive ROS in the injured tendon, down-regulate the inflammatory response, enhance the tendon differentiation of tendon stem cells, promote intrinsic healing, and ultimately promote the repair of injured tendons. Furthermore, the system can accelerate the transition from inflammation to repair and remodeling in the tendon healing process. The PVA/PEG/ZIF-8@CeO2 treatment system is a novel approach for reducing peritendinous adhesions and effectively promoting the repair of injured tendons.

Heat stress negatively affects pig production by disrupting the immune homeostasis of Sertoli cells (SCs), which compromises sperm quality, culminating in male infertility. Herein, we aimed to study the mechanism by which the NLRP3 inflammasome is activated by heat stress through N6-methyladenosine (m6A) modification regulation in SCs. Initially, it was found that heat stress (44°C, 30 min) markedly activated ERK1/2 signaling, which subsequently promoted NLRP3 inflammasome activation and inflammatory cytokine release from SCs. Then, using an m6A dot-blot assay, m6A sequencing, and methylated RNA immunoprecipitation, we found that heat stress augmented the level of m6A modification in SCs, and METTL3 augmented the m6A modification of mRNA encoding SOS Ras/Rho guanine nucleotide exchange factor 2 (SOS2), a key activator of the ERK pathway. Furthermore, YTHDF1 recognized and bound to the m6A-modified SOS2 mRNA to enhance its translation efficiency, ultimately triggering ERK1/2 signaling activation. In vivo experiments demonstrated that heat stress-induced decline in semen quality in mice was associated with elevated levels of m6A modifications in the testis and NLRP3 inflammasome activation. However, the damage caused by heat stress could be attenuated by intraperitoneal injection of S-Adenosylhomocysteine (SAH), a specific methyltransferase inhibitor. Our results emphasize the critical roles of m6A in regulating NLRP3 inflammasome activation under heat stress, identifying a novel therapeutic avenue to address heat stress.

Silk fibroin (SF), derived from silk cocoon fibers (Bombyx mori), is a natural protein polymer known for its biocompatibility, biodegradability, and sustainability. The protein can be processed into various material formats suitable for a range of applications. Among these, SF hydrogels are useful in the biomedical field, such as tissue engineering, due to the tailorable structures and properties achievable through tuning the gelation process. Therefore, the focus of this contribution is to comprehensively review and understand the formation, gelation mechanism, dynamic control, and functionalization of SF hydrogels. Unlike previous reviews, this work delves into understanding the strategies and mechanisms for tuning the gelation dynamics of SF from molecular assembly and crystallization points of view. Further, this review presents functionalization pathways and practical examples, such as for the 3D printing of SF hydrogels, to illustrate how these strategies, mechanisms, and pathways can be implemented in a specific application scenario. With these insights, researchers can gain a deeper understanding of how to manipulate or control the gelation process and the types of functionalization to achieve specific properties and features. This knowledge would further facilitate the development and application of SF hydrogel materials in various fields.

Non-healing diabetic wounds often culminate in amputation and mortality. The main pathophysiological features in diabetic wounds involve the accumulation of M1-type macrophages and excessive oxidative stress. In this study, we engineered a nano-enzyme functionalized hydrogel by incorporating a magnesium ion-doped molybdenum-based polymetallic oxide (Mg-POM), a novel bioactive nano-enzyme, into a GelMA hydrogel, to obtain the GelMA@Mg-POM system to enhance diabetic wound healing. GelMA@Mg-POM was crosslinked using UV light, yielding a hydrogel with a uniformly porous three-dimensional mesh structure. In vitro experiments showed that GelMA@Mg-POM extraction significantly enhanced human umbilical vein endothelial cell (HUVEC) migration, scavenged ROS, improved the inflammatory microenvironment, induced macrophage reprogramming towards M2, and promoted HUVEC regeneration of CD31 and fibroblast regeneration of type I collagen. In in vivo experiments, diabetic rat wounds treated with GelMA@Mg-POM displayed enhanced granulation tissue genesis and collagen production, as evidenced by HE and Masson staining. Immunohistochemistry demonstrated the ability of GelMA@Mg-POM to mitigate macrophage-associated inflammatory responses and promote angiogenesis. Overall, these findings suggest that GelMA@Mg-POM holds significant promise as a biomaterial for treating diabetic wounds.

The central nervous system's limited capacity for regeneration often leads to permanent neuronal loss following injury. Reprogramming resident reactive astrocytes into induced neurons at the site of injury is a promising strategy for neural repair, but challenges persist in stabilizing and accurately targeting viral vectors for transgene expression. In this study, we employed a bioinspired self-assembling peptide (SAP) hydrogel for the precise and controlled release of a hybrid adeno-associated virus (AAV) vector, AAVDJ, carrying the NeuroD1 neural reprogramming transgene. This method effectively mitigates the issues of high viral dosage at the target site, off-target delivery, and immunogenic reactions, enhancing the vector's targeting and reprogramming efficiency. In vitro, this vector successfully induced neuron formation, as confirmed by morphological, histochemical, and electrophysiological analyses. In vivo, SAP-mediated delivery of AAVDJ-NeuroD1 facilitated the trans-differentiation of reactive host astrocytes into induced neurons, concurrently reducing glial scarring. Our findings introduce a safe and effective method for treating central nervous system injuries, marking a significant advancement in regenerative neuroscience.

Injectable biomimetic hydrogels have great potential for use in regenerative medicine as cellular delivery vectors. However, they can suffer from issues relating to hypoxia, including poor cell survival, differentiation, and functional integration owing to the lack of an established vascular network. Here we engineer a hybrid myoglobin:peptide hydrogel that can concomitantly deliver stem cells and oxygen to the brain to support engraftment until vascularisation can occur naturally. We show that this hybrid hydrogel can modulate cell fate specification within progenitor cell grafts, resulting in a significant increase in neuronal differentiation. We find that the addition of myoglobin to the hydrogel results in more extensive innervation within the host tissue from the grafted cells, which is essential for neuronal replacement strategies to ensure functional synaptic connectivity. This approach could result in greater functional integration of stem cell-derived grafts for the treatment of neural injuries and diseases affecting the central and peripheral nervous systems.

Gene therapy offers hope for currently untreatable diseases; the patient’s own cellular machinery is recruited to create therapeutics. However, unpredictable responses that lead to neutralization by the host immune system and issues in constraining, controlling and sustaining delivery have presented clinical barriers to otherwise promising therapeutic developments. Here, we show that the protective environment provided by advanced biomaterials can function as injectable gene carriers to focus their therapeutic potential. Firstly, we investigated the potential of a tissue-specific molecular hydrogel to package recombinant adeno-associated viruses (rAAVs). Once a delivery pathway was confirmed, a set of rAAV variants were subsequently assessed for their ability to transduce various types of rodent and human neural cells in vitro and in vivo. Based on GFP expression, we identified a relatively new variant, rAAV-DJ, as showing desirable characteristics for constrained delivery and transduction efficiency. For the first time, we demonstrated precise control over the strength and type of interaction between biomaterials and rAAVs enabling the programmed release of viral payloads. This new approach enables specific infection of desired anatomical targets in a programmed fashion.

Many materials have been engineered and commercialized as hemostatic agents. However, there is still a gap in the availability of hemostats that offer biocompatibility and biodegradability in combination with effective hemostatic properties. Cellulose nanofibers are investigated as hemostatic materials with most studies focusing on oxidized cellulose-derived hemostats. The recent studies demonstrate that by optimizing the morphological properties of nonoxidized cellulose nanofibers (CNFs) enhanced hemostasis is achieved. Herein, the hemostatic and wound-healing properties of CNFs with optimized morphology using two forms, gel, and sponge is investigated. In vitro thromboelastometry studies demonstrate that CNFs reduce clotting time by 68% (±SE 2%) and 88% (±SE 5%) in gel and sponge forms, respectively. In an in vivo murine liver injury model, CNFs significantly reduce blood loss by 38% (±SE 10%). The pH-neutral CNFs do not damage red blood cells, nor do they impede the proliferation of fibroblast or endothelial cells. Subcutaneously-implanted CNFs show a foreign body reaction resolving with the degradation of CNFs on histological examination and there is no scarring in the skin after 8 weeks. Demonstrating superior hemostatic performance in a variety of forms, as well as biocompatibility and biodegradability, CNFs hold significant potential for use in surgical and first-aid environments.

Clinical studies have provided evidence for dopamine (DA) cell replacement therapy in Parkinson’s Disease. However, grafts derived from foetal tissue or pluripotent stem cells (PSCs) remain heterogeneous, with a high proportion of non-dopaminergic cells, and display subthreshold reinnervation of target tissues, thereby highlighting the need to identify new strategies to improve graft outcomes. In recent work, Stromal Cell-Derived Factor-1 (SDF1), secreted from meninges, has been shown to exert many roles during ventral midbrain DA development and DA-directed differentiation of PSCs. Related, co-implantation of meningeal cells has been shown to improve neural graft outcomes, however, no direct evidence for the role of SDF1 in neural grafting has been shown. Due to the rapid degradation of SDF1 protein, here, we utilised a hydrogel to entrap the protein and sustain its delivery at the transplant site to assess the impact on DA progenitor differentiation, survival and plasticity. Hydrogels were fabricated from self-assembling peptides (SAP), presenting an epitope for laminin, the brain’s main extracellular matrix protein, thereby providing cell adhesive support for the grafts and additional laminin–integrin signalling to influence cell fate. We show that SDF1 functionalised SAP hydrogels resulted in larger grafts, containing more DA neurons, increased A9 DA specification (the subpopulation of DA neurons responsible for motor function) and enhanced innervation. These findings demonstrate the capacity for functionalised, tissue-specific hydrogels to improve the composition of grafts targeted for neural repair.

The defined self-assembly of peptides (SAPs) into nanostructured bioactive hydrogels has great potential for repairing traumatic brain injuries, as they maintain a stable, homeostatic environment at an injury site, preventing further degeneration. They also present a bespoke platform to restore function via the naturalistic presentation of therapeutic proteins, such as stromal-cell-derived factor 1 (SDF-1), expressed by meningeal cells. A key challenge to the use of the SDF protein, however, is its rapid diffusion and degradation. Here, we engineered a homeostatic hydrogel produced by incorporating recombinant SDF-1 protein within a self-assembled peptide hydrogel to create a supportive milieu for transplanted cells. Our hydrogel can concomitantly deliver viable primary neural progenitor cells and sustained active SDF-1 to support the nascent graft, resulting in increased neuronal differentiation. Moreover, this homeostatic hydrogel can ensure a healthy and larger graft core without impeding neuronal fiber growth and innervation. These findings demonstrate the regenerative potential of these hydrogels to improve the integration of grafted cells to treat neural injuries and diseases.

The spread of viral and bacterial pathogens mediated by contact with surfaces is a leading cause of infection worldwide. COVID-19 and the continuous rise of deaths associated with antibiotic-resistant bacteria highlight the need to impede surface-mediated transmission. A sprayable coating with an intrinsic ability to resist the uptake of bacteria and viruses from surfaces and droplets, such as those generated by sneezing or coughing, is reported. The coating also provides an effective microbicidal functionality against bacteria, providing a dual barrier against pathogen uptake and transmission. This antimicrobial functionality is fully preserved following scratching and other induced damage to its surface or 9 days of submersion in a highly concentrated suspension of bacteria. The coatings also register an 11-fold decrease in viral contamination compared to the noncoated surfaces.

The survival and synaptic integration of transplanted dopaminergic (DA) progenitors are essential for ameliorating motor symptoms in Parkinson's disease (PD). Human pluripotent stem cell (hPSC)‐derived DA progenitors are, however, exposed to numerous stressors prior to, and during, implantation that result in poor survival. Additionally, hPSC‐derived grafts show inferior plasticity compared to fetal tissue grafts. These observations suggest that a more conducive host environment may improve graft outcomes. Here, tissue‐specific support to DA progenitor grafts is provided with a fully characterized self‐assembling peptide hydrogel. This biomimetic hydrogel matrix is programmed to support DA progenitors by i) including a laminin epitope within the matrix; and ii) shear encapsulating glial cell line‐derived neurotrophic factor (GDNF) to ensure its sustained delivery. The biocompatible hydrogel biased a 51% increase in A9 neuron specification—a subpopulation of DA neurons critical for motor function. The sustained delivery of GDNF induced a 2.7‐fold increase in DA neurons and enhanced graft plasticity, resulting in significant improvements in motor deficits at 6 months. These findings highlight the therapeutic benefit of stepwise customization of tissue‐specific hydrogels to improve the physical and trophic support of human PSC‐derived neural transplants, resulting in improved standardization, predictability and functional efficacy of grafts for PD.

Cell transplantation is one of the most promising strategies for the minimally invasive treatment of a raft of injuries and diseases. However, a standing challenge to its efficacy is poor cell survival due to a lack of mechanical protection during administration and an unsupportive milieu thereafter. In response, a shear-injectable nanoscaffold vector is engineered considering the three equal requirements of protection, support, and survival. Here, the programmed peptide assembly of tissue-specific epitopes presents a safe sanctuary microenvironment for the transplantation of cells. For the first time, a mechanistic understanding of the multifactorial role of the nanoscaffold in promoting cell survival is presented, where initial cell survival is dependent on the fluid mechanic process of droplet formation rather than on shear rate. However, provided is the first report of the most critical component of a transplantation vector, distinguishing feigned biological support from mechanical properties from true ongoing biological support post transplantation. This is achieved via the presentation of amino acid constituents that significantly improve the efficacy of the vector compared to a biocompatible, yet inert analogue. Together, the peptide-programmed hydrogels enable fundamental rules for the engineering of advanced treatment strategies with wide reaching implications for tissue repair and biofabrication.

In article number 1900390, Richard J. Williams, David R. Nisbet, and co-workers report on a peptide hydrogel programmed for the minimally invasive transplantation of stem cells. The cell-laden droplets formed by the hydrogel protect cells during syringe administration. The hydrogel then ‘switches’ to offer long-term bioactive support. These insights will have a significant impact for tissue repair, biofabrication, drugs, and cellinstructive 3D cultures.

Gene delivery has been extensively investigated for introducing foreign genetic material into cells to promote expression of therapeutic proteins or to silence relevant genes. This approach can regulate genetic or epigenetic disorders, offering an attractive alternative to pharmacological therapy or invasive protein delivery options. However, the exciting potential of viral gene therapy has yet to be fully realized, with a number of clinical trials failing to deliver optimal therapeutic outcomes. Reasons for this include difficulty in achieving localized delivery, and subsequently lower efficacy at the target site, as well as poor or inconsistent transduction efficiency. Thus, ongoing efforts are focused on improving local viral delivery and enhancing its efficiency. Recently, biomaterials have been exploited as an option for more controlled, targeted and programmable gene delivery. There is a growing body of literature demonstrating the efficacy of biomaterials and their potential advantages over other delivery strategies. This review explores current limitations of gene delivery and the progress of biomaterial-mediated gene delivery. The combination of biomaterials and gene vectors holds the potential to surmount major challenges, including the uncontrolled release of viral vectors with random delivery duration, poorly localized viral delivery with associated off-target effects, limited viral tropism, and immune safety concerns.

Adenosine monophosphate-activated protein kinase (AMPK) plays a key role in cellular energy homeostasis and cell proliferation. MicroRNAs (miRNAs) function as posttranscriptional regulators of gene expression in biological processes. It is unclear to whether miRNAs are involved in AMPK-regulated Sertoli cell (SC) proliferation. To further understand the regulation of miRNAs in the immature boar SC proliferation, 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) was added to activate AMPK. By an Illumina small RNA deep sequencing, we obtained sequences and relative expression levels of 272 known mature miRNAs, among which 9 miRNAs were significantly upregulated whereas 16 miRNAs were downregulated following the AICAR treatment. The results identified 38 conserved miRNAs, with 8 significantly downregulated miRNAs whereas no upregulated miRNAs. Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses suggested that miR-1285 was involved in many activities and pathways associated with cell proliferation via targeting on AMPKα2. We validated that AICAR significantly downregulated miR-1285 level in SCs. Transfection of miR-1285 mimic increased the SC viability and cell cycle progression but reduced AMPKα2 mRNA and protein levels, indicating that miR-1285 is involved in the immature boar SC proliferation via downregulating AMPKα2 expression.

The remarkable catalytic potential of enzymes in chemical synthesis, environmental bioremediation, and medical therapeutics is limited by their longevity and stability. Immobilization of enzymes on solid supports is demonstrated to improve the stability of biocatalysts but often relies on multiple chemical steps for covalent attachment and is limited by the physical properties of the various supports. Here, production of enzyme: hydrogel complexes is described via engineering of a cationic supercharged phosphotriesterase. These enzyme: hydrogel complexes are remarkably robust displaying no loss of catalytic activity after 80 d of use and up to 10 5 turnovers when used in a flow reactor at catalyst loadings as low as 0.0008 mol%. In addition, exceptional resilience to organic solvents is observed. The use of enzyme: hydrogel complexes is likely to be of value in a diverse range of applications such as enantioselective continuous‐flow chemistry, detoxification of poisons, and the formation of functionalized biomaterials.