Zn2 SiO4 Bioceramic Attenuates Cardiac Remodeling after Myocardial Infarction

LIPUS activated piezoelectric pPLLA/SrSiO3 composite scaffold promotes osteochondral regeneration through P2RX1 mediated Ca2+ signaling pathway

Addressing the concurrent repair of cartilage and subchondral bone presents a significant challenge yet is crucial for the effective treatment of severe joint injuries. This study introduces a novel biodegradable composite scaffold, integrating piezoelectric poly-l-lactic acid (pPLLA) with strontium-enriched silicate bioceramic (SrSiO3). This innovative scaffold continually releases bioactive Sr2+ and SiO32- ions while generating an electrical charge under low-intensity pulsed ultrasound (LIPUS) stimulation, a clinically recognized method. The scaffold's unique dual action, emanating both chemical and electrical signals, activates the purinergic receptor P2X 1 (P2RX1) calcium ion channel, promoting an influx of intracellular calcium ions. This process results in a synergistic enhancement of both chondrogenic activities of rat chondrocytes (rCCs) and osteogenic activities of rat bone marrow mesenchymal stem cells (rBMSCs). Furthermore, the scaffold's effectiveness in integrating articular cartilage and subchondral bone repair is confirmed in a rat model of joint osteochondral injury. This study thereby offers a groundbreaking approach for treating severe osteoarticular cartilage defects.

Silicate-based therapy for inflammatory dilated cardiomyopathy by inhibiting the vicious cycle of immune inflammation via FOXO signaling

Inflammatory dilated cardiomyopathy (iDCM) represents a severe immune-related condition provoked by the progression of myocarditis. In patients suffering from myocarditis, a vicious cycle of inflammation orchestrated by CD4+ T cells, neutrophils, and fibroblasts is the culprit that drives the deterioration of myocarditis into iDCM. This study designed composite microneedles and ion solutions using calcium silicate bioceramics, which deliver SiO32- directly into myocardial tissue or indirectly via systemic circulation. These interventions modulate the cell microenvironment by regulating CD4+ T/T helper 17 (TH17) cells and their interactions with neutrophils and fibroblasts through the forkhead box O (FOXO) signaling pathway. Specifically, SiO32- inhibits the hyperdifferentiation of CD4+ T cells to TH17 cells by regulating FOXO1 and neutrophils to neutrophil extracellular traps as well as fibroblasts to myofibroblasts by regulating FOXO3, thereby ultimately disrupting the vicious cycle of myocardial inflammation and subsequent fibrotic lesions in iDCM. This discovery indicates that the biomaterial-based strategy may have great potential for the treatment of iDCM.

Copper hydrogen phosphate nanosheets functionalized hydrogel with tissue adhesive, antibacterial, and angiogenic capabilities for tracheal mucosal regeneration

Timely and effective interventions after tracheal mucosal injury are lack in clinical practices, which elevate the risks of airway infection, tracheal cartilage deterioration, and even asphyxiated death. Herein, we proposed a biomaterial-based strategy for the repair of injured tracheal mucosal based on a copper hydrogen phosphate nanosheets (CuHP NSs) functionalized commercial hydrogel (polyethylene glycol disuccinimidyl succinate-human serum albumin, PH). Such CuHP/PH hydrogel achieved favorable injectability, stable gelation, and excellent adhesiveness within the tracheal lumen. Moreover, CuHP NSs within the CuHP/PH hydrogel effectively stimulate the proliferation and migration of endothelial/epithelial cells, enhancing angiogenesis and demonstrating excellent tissue regenerative potential. Additionally, it exhibited significant inhibitory effects on both bacteria and bacterial biofilms. More importantly, when injected injured site of tracheal mucosa under fiberoptic bronchoscopy guidance, our results demonstrated CuHP/PH hydrogel adhered tightly to the tracheal mucosa. The therapeutic effects of the CuHP/PH hydrogel were further confirmed, which significantly improved survival rates, vascular and mucosal regeneration, reduced occurrences of intraluminal infections, tracheal stenosis, and cartilage damage complications. This research presents an initial proposition outlining a strategy employing biomaterials to mitigate tracheal mucosal injury, offering novel perspectives on the treatment of mucosal injuries and other tracheal diseases.

Advances in Functionalized Hydrogels in the Treatment of Myocardial Infarction and Drug-Delivery Strategies

Myocardial infarction (MI) is a serious cardiovascular disease with high morbidity and mortality rates, posing a significant threat to patient's health and quality of life. Following a MI, the damaged myocardial tissue is typically not fully repaired, leading to permanent impairment of myocardial function. While traditional treatments can alleviate symptoms and reduce pain, their ability to repair damaged heart muscle tissue is limited. Functionalized hydrogels, a broad category of materials with diverse functionalities, can enhance the properties of hydrogels to cater to the needs of tissue engineering, drug delivery, medical dressings, and other applications. Recently, functionalized hydrogels have emerged as a promising new therapeutic approach for the treatment of MI. Functionalized hydrogels possess outstanding biocompatibility, customizable mechanical properties, and drug-release capabilities. These properties enable them to offer scaffold support, drug release, and tissue regeneration promotion, making them a promising approach for treating MI. This paper aims to evaluate the advancements and delivery methods of functionalized hydrogels for treating MI, while also discussing their potential and the challenges they may pose for future clinical use.

Strontium zinc silicate simultaneously alleviates osteoporosis and sarcopenia in tail-suspended rats via Piezo1-mediated Ca2+ signaling

Background

Long-term physical inactivity probably leads to a co-existence of osteoporosis and sarcopenia which result in a high risk of falls, fractures, disability and even mortality. However, universally applicable and feasible approaches are lacking in the concurrent treatment of osteoporosis and sarcopenia. In this study, we evaluated the effect of strontium zinc silicate bioceramic (SZS) extract on osteoporosis and sarcopenia and explored its underlying mechanisms.

Methods

Hindlimb osteoporosis and sarcopenia were established in a tail-suspended rat model. The bones were conducted μCT scanning, histological examination, and gene expression analysis, and the muscles were conducted histological examination and gene expression analysis. In vitro, the effect of SZS extract on osteoblasts was determined by alizarin red S staining, immunofluorescence and qPCR. Similarly, the effect of SZS extract on myoblasts was determined by immunofluorescence and qPCR.. At last, the role of Piezo1 and the change of intracellular calcium ion (Ca2+) were explored through blockading the Piezo1 by GsMTx4 in MC3T3-E1 and C2C12 cells, respectively.

Results

We found that SZS extract could concurrently and efficiently prevent bone structure deterioration, muscle atrophy and fibrosis in hind limbs of the tail-suspended rats. The in vivo study also showed that SZS extract could upregulate the mRNA expression of Piezo1, thereby maintaining the homeostasis of bones and muscles. In vitro study demonstrated that SZS extract could promote the proliferation and differentiation of MC3T3-E1 and C2C12 cells by increasing the intracellular Ca2+ in a Piezo1-dependent manner.

Conclusion

This study demonstrated that SZS extract could increase Piezo1-mediated intracellular Ca2+, and facilitate osteogenic differentiation of osteoblast and myogenic differentiation of myoblasts, contributing to alleviation of osteoporosis and sarcopenia in a tail-suspended rat model.

The translational potential of this article

The current study might provide a universally applicable and efficient strategy to treat musculoskeletal disorders based on bioactive ceramics. The verification of the role of Piezo1-modulated intracellular Ca2+ during osteogenesis and myogenesis provided a possible therapeutic target against mechanical related diseases.

Design of a Zn-based nanozyme injectable multifunctional hydrogel with ROS scavenging activity for myocardial infarction therapy

The existing strategies for myocardial infarction therapy mainly focus on reinstating myocardial blood supply, often disregarding the intrinsic and intricate microenvironment created by elevated levels of reactive oxygen species (ROS) that accompanies myocardial infarction. This microenvironment entails cardiomyocytes apoptosis, substantial vascular cell death, excessive inflammatory infiltration and fibrosis. In such situation, the present study introduces a zinc-based nanozyme injectable multifunctional hydrogel, crafted from ZIF-8, to counteract ROS effects after myocardial infarction. The hydrogel exhibits both superoxide dismutase (SOD)-like and catalase (CAT)-like enzymatic activities, proficiently eliminating surplus ROS in the infarcted region and interrupting ROS-driven inflammatory cascades. Furthermore, the hydrogel's exceptional immunomodulatory ability spurs a notable transformation of macrophages into the M2 phenotype, effectively neutralizing inflammatory factors and indirectly fostering vascularization in the infarcted region. For high ROS and demanding for zinc of the infarcted microenvironment, the gradual release of zinc ions as the hydrogel degrades further enhances the bioactive and catalytic performance of the nanozymes, synergistically promoting cardiac function post myocardial infarction. In conclusion, this system of deploying catalytic nanomaterials within bioactive matrices for ROS-related ailment therapy not only establishes a robust foundation for biomedical material development, but also promises a holistic approach towards addressing myocardial infarction complexities. STATEMENT OF SIGNIFICANCE: Myocardial infarction remains the leading cause of death worldwide. However, the existing strategies for myocardial infarction therapy mainly focus on reinstating myocardial blood supply. These therapies often ignore the intrinsic and intricate microenvironment created by elevated levels of reactive oxygen species (ROS). Hence, we designed an injectable Zn-Based nanozyme hydrogel with ROS scavenging activity for myocardial infarction therapy. ALG-(ZIF-8) can significantly reduce ROS in the infarcted area and alleviate the ensuing pathological process. ALG-(ZIF-8) gradually releases zinc ions to participate in the repair process and improves cardiac function. Overall, this multifunctional hydrogel equipped with ZIF-8 makes full use of the characteristics of clearing ROS and slowly releasing zinc ions, and we are the first to test the therapeutic efficacy of Zinc-MOFs crosslinked-alginate hydrogel for myocardial infarction.

Platelet Membrane-Encapsulated Nanocomplexes Based on Profundity Scavenging ROS Strategy for Myocardial Infarction Therapy

Ischemia-induced myocardial injury has become a serious threat to human health, and its treatment remains a challenge. The occurrence of ischemic events leads to a burst release of reactive oxygen species (ROS), which triggers extensive oxidative damage and leads to dysfunctional autophagy, making it difficult for cells to maintain homeostasis. Antioxidants and modulation of autophagy have thus become promising strategies for the treatment of ischemic myocardial injury. This study proposes an antioxidant-activated autophagy therapeutic regimen based on combining melanin (Mel), an excellent antioxidant with metformin mimetic ploymetformin via electrostatic interactions, to obtain a nanocomplex (Met-Mel). The nanocomplex is finally encapsulated with platelet membranes (PMN) to construct a biomimetic nanoparticle (PMN@Met-Mel) capable of targeting injured myocardium. The prepared PMN@Met-Mel has good Mel loading capacity and optimal biosafety. It exhibits excellent antioxidant activity and autophagy activation, rapidly restoring mitochondrial function. Moreover, RNA sequencing (RNA-seq) analysis reveals that PMN@Met-Mel operates mechanistically by triggering the activation of the autophagy pathway. Subsequent in vivo experiments showcase promising cardioprotective effects of these nanoparticles. These discoveries present a newly devised nanoplatform with promising potential for the effective treatment of myocardial infarction.

Bredigite-Based Bioactive Nerve Guidance Conduit for Pro-Healing Macrophage Polarization and Peripheral Nerve Regeneration

Structural and functional healing of peripheral nerves damaged by trauma or chronic disease remain major clinical challenges, requiring the development of an effective nerve guidance conduit (NGC). The present study investigates a NGC fabrication strategy based on bredigite (BRT, Ca7MgSi4O16) bioceramic for the treatment of peripheral nerve injury. Here, BRT bioceramic shows good biocompatibility and sustainable release of Ca2+, Mg2+, and Si4+ ions. Both BRT extracts and BRT-incorporating electrospun membranes promote the proliferation and myelination potential of RSC96 cells, as well as accelerate vascular formation by human umbilical vein endothelial cells. Notably, BRT facilitates RAW 264.7 cell polarization to the pro-healing phenotype under LPS-induced inflammatory stimulation. More importantly, the macrophages activated by BRT in turn promote RSC96 cell migration and remyelination. In a rat sciatic nerve defect model, improved electrophysiological performance and alleviated gastrocnemius muscle atrophy are observed at 12 weeks post-implantation. Further experiments verify that BRT-loaded NGC facilitates axonal regrowth and revascularization with high M2-like macrophage infiltration. These findings support the beneficial effects of BRT for creating a pro-healing immune microenvironment and orchestrating multicellular processes associated with functional nerve regeneration, indicating the potential of rationally engineered bioceramics as safe, effective, and economical materials for peripheral nerve repair.

Photothermal-Ionic-Pharmacotherapy of Myocardial Infarction with Enhanced Angiogenesis and Antiapoptosis

Promoting angiogenesis is an effective therapeutic strategy to repair damaged hearts after myocardial infarction (MI). Copper ions and mild heat (41-42 °C) have been shown to promote angiogenesis, but their efficacy in MI is unknown. Here, a multicomponent hydrogel (EDR@PHCuS HG) is developed by encapsulating edaravone (EDR, a free radical scavenger) loaded porous hollow copper sulfide nanoparticles (PHCuS NPs) in a hyaluronic acid hydrogel (HG). Exposed to 808 nm near-infrared (NIR) light irradiation, the EDR@PHCuS HG exhibits controlled copper-ion release and mild photothermal effect to synergistically promote angiogenesis. In addition, released EDR inhibits cardiomyocyte apoptosis to further repair hearts. In the mouse model of MI, treatment with the EDR@PHCuS HG under an 808 nm laser significantly recovers the cardiac function and inhibits ventricular remodeling. This platform elucidates the cardioprotective effects of copper ions and mild heat and will provide a highly efficient treatment for MI.