Hydrogel microspheres are important in regenerative medicine and tissue engineering, acting as cargos of cells, drugs, growth factors, bio-inks for 3D printing, and medical devices. The antimicrobial and anti-inflammatory characteristics of hydrogel microspheres are good for treating injured tissues. However, the biological properties of hydrogel microspheres should be modified for optimal treatment of various body parts with different physiological and biochemical environments. In addition, specific preparation methods are required to produce customized hydrogel microspheres with different shapes and sizes for various clinical applications. Herein, the advances in hydrogel microspheres for biomedical applications are reviewed. Synthesis methods for hydrogel precursor solutions, manufacturing methods, and strategies for enhancing the biological functions of these hydrogel microspheres are described. The involvement of bioactive hydrogel microspheres in tissue repair is also discussed. This review anticipates fostering more insights into the design, production, and application of hydrogel microspheres in biomedicine.

Skin trauma, especially chronic trauma, poses a significant clinical challenge, often leading to severe disability or even death. Traditional treatment methods exhibit several limitations in terms of efficacy, material availability, and biocompatibility. The development of decellularized extracellular matrices (dECMs) has led to revolutionary progress in this field. These materials retain the bioactive components of the natural extracellular matrix (ECM) and, combined with their excellent physical structure, promote wound healing. Preclinical studies have demonstrated that dECM-based dressings can enhance the re-epithelialization rate by 20–50% and shorten the healing cycle of chronic wounds by 40%. This article systematically reviews the application of dECM in wound repair. First, it outlines the pathophysiology of wound healing, focusing on the mechanisms by which key ECM components promote wound healing. Next, it classifies decellularized materials and proposes material design schemes for different types of damage. Finally, the limitations of current dECM-based wound treatments and future research directions are discussed. This review aims to provide a theoretical framework and technical reference for researchers in related fields, promoting the widespread application of dECM materials for skin trauma treatment.

Ulcerative colitis (UC) is a chronic and recurrent intestinal disease of unknown aetiology, and the few treatments approved for UC have serious side effects. In this study, a new type of uniformly monodispersed calcium-enhanced radial mesoporous micro-nano bioactive glass (HCa-MBG) was prepared for UC treatment. We established cellular and rat UC models to explore the effects and mechanism of HCa-MBG and traditional BGs (45S5, 58S) on UC. The results showed that BGs significantly reduced the cellular expression of several inflammatory factors, such as IL-1β, IL-6, TNF-α and NO. In the animal experiments, BGs were shown to repair the DSS-damaged colonic mucosa. Moreover, BGs downregulated the mRNA levels of the inflammatory factors IL-1β, IL-6, TNF-α and iNOS, which were stimulated by DSS. BGs were also found to manage the expression of key proteins in NF-kB signal pathway. However, HCa-MBG was more effective than traditional BGs in terms of improving UC clinical manifestations and reducing the expression of inflammatory factors in rats. This study confirmed for the first time that BGs can be used as an adjuvant drug in UC treatment, thereby preventing UC progression.

Recently, highly abundant natural materials have been used in the fields of energy storage because of their environmental friendliness and low cost. However, use of some natural materials like cellulose as host matrices of gel polymer electrolytes (GPEs) is challenging owing to the strong intra- and inter-molecular hydrogen bonding. Herein, a green GPE film was prepared by chemically grafting soft chain-polyethylene glycol (PEG) onto the backbone of cellulose. The introduction of PEG significantly improved the toughness of cellulose from 118 x 103 to 270 x 103 kJ m- 3, as well as raised the wettability in carbonate-based liquid electrolyte solutions from 22.6% to 141.7%. The first cycle coulomb efficiency stayed above 90%. The capacity retention of LiFePO4/ Li batteries assembled with the as-obtained GPE reached 80.3% after 300 cycles at 0.2 C. In sum, the as-obtained cellulose-based GPEs look promising to replace separators and liquid electrolytes in Li-ion batteries.

Gel polymer electrolytes (GPEs) combine the high ionic conductivity of liquid electrolytes and good safety assurance of solid electrolytes. However, the poor interfacial contact between electrode materials and electrolyte is still a big obstacle to the high performance of solid-state batteries. Herein, an integrated cathode/GPE based on continuous composition and preparation technic is obtained by simple UV curing. The improved interfacial contact between cathode and GPE helps to facilitate the fast ions transfer at the interface. Compared with cells assembled with separated cathode and GPE, the cells with integrated cathode-GPE showed much lower interfacial impedance, lower potential polarization and more stable cycling property. This work provided a low-cost natural material gelatin and a simple UV irradiation method to prepare an integrated cathode and gel polymer electrolyte for solid-state lithium batteries. The capacity retention of the cells assembled from integrated structure was 91.4% which was much higher than that of the non-integrated cells (80.9%) after 200 cycles.

A novel uniform monodispersed radial mesoporous bioactive glass nanosphere (MBG) with high phosphorus and calcium content has been successfully synthesized. The synthesis was first taken place in a cyclohexane-water biphasic stratification reaction system, which fabricated the radial mesoporous SiO2-P2O5 nanosphere (SPN) using hexadecyltrimethyl ammonium bromide (CTAB) as a template agent and triethanolamine (TEA) as a hydrolysis catalyst. Solid reactions were then carried out to synthesize SiO2-CaO-P2O5 MBG using SPN as both the silicon source and phosphorus source, and Ca(NO3)(2) as the calcium source. The prepared MBG not only displayed the radial structure and high specific surface area (similar to 321 m(2)/g), but also had high phosphorus and calcium content. The results of energy dispersive spectrometer (EDS) demonstrated that P2O5 content was enhanced by properly increasing the reaction temperature. The in vitro bioactivity test showed that MBG had an excellent ability of inducing apatite formation. Furthermore, the MBG showed excellent biocompatibility at a low concentration of 50-100 lg/mL in vitro, and it would have a promising prospect as drug delivery system for bone tissue regeneration. (C) 2020 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.

With the advent of gel polymer electrolyte (GPE), a series of safety problems of lithium ion batteries have been resolved. However, poor self-standing property, the low ionic conductivity and Li+ transference number are still the obstacles that impede the practical application of GPE. Herein, a flexible and eco-friendly GPE is designed using allyl-modified cellulose with methylcellulose through simple UV curing. The crosslinked structure facilitates the integrity of GPE during use, and methylcellulose guarantees the high affinity to liquid electrolyte and improve interfacial compatibility. The specific polar functional groups (OH, OCH3 and COC) in GPE cooperate to enhance the lithium salt dissociation, anion immobilization and lithium ion transporting and enable the high Li+ transference number (0.902) and ion conductivity (4.36 × 10-3 S cm-1). The assembled Li/GPE/LiFePO4 coin cells possess high initial discharge capacity of 150.6 mA h g-1 and a high capacity retention of 91.6 % after 100 cycles.

Lithium iron phosphate (LiFePO4) is one of the most widely used cathode materials of lithium ion batteries. However, its commercial binder polyvinylidene fluoride (PVDF) is costly, less environmental-friendly and unstable during the long cycling process because of the weak van der Waals forces between the PVDF binder and electrode materials. Herein, an aqueous binder was designed using methacrylate-modified gelatin through UV photo-crosslinking. The crosslinked network and specific functional groups (carboxyl and amino) of the gelatin binder are superior in stabilizing the LiFePO(4)electrode structure during long cycles by mitigating the formation of cracks and suppressing the detachment of electrode materials from the Al current collector. The LiFePO(4)electrode with gelatin binder displays a high capacity of 140.3 mA h g(-1)with 90.1% retention after 300 cycles at 0.5C, which are both superior to that of the PVDF binder (only 114.4 mA h g(-1)and 74.8%). This work provides a promising binder to replace the commercial PVDF binder for practical application in energy storage systems.

采用溶胶-凝胶结合碱性共沉淀法和冷冻干燥技术制备纳米生物活性玻璃(NBG),通过SEM、TEM、激光粒度考察NBG的形貌、分散性和粒径,并通过四唑盐比色法(MTT)研究其浸提液对人成纤维细胞(HDF)增殖性能的影响.结果 显示,NBG颗粒粒径小于50 nm,激光粒度仪检测到的平均粒径为491.8 nm,相比于溶胶-凝胶生物活性玻璃(SGBG),NBG平均粒径更小,分散性更好.NBG与SGBG浸提液在5倍、10倍和15倍稀释的浓度下均有利于HDF的增殖,但SGBG在早期稍有利于细胞增殖但作用不明显,而NBG则在后期对细胞增殖作用更显著,因此NBG在创面修复方面更具有应用前景.

Mesoporous bioactive glass microspheres (MBGMs) with large mesopores have attracted considerable attention in the field of bone tissue regeneration and drug delivery systems due to their excellent bioactivity, biocompatibility and high specific area. In this study, a loose structure of MBGMs with adjustable chemical compositions was synthesized by the combination of sol-gel and water-in-oil (W/O) microemulsion. All the prepared MBGMs possessed a large mesopore diameter that increased with CaO content, a high surface area and good apatite-inducing formation ability. In vitro protein absorption and release assays demonstrated that the MBGMs exhibited decreased loading efficiency and burst release behavior as the CaO content increased. Additionally, an enhanced BSA-loading amount and prolonged release curve were obtained after the surfaces of MBGMs were modified by amine groups. Furthermore, the preliminary in vitro cell experiments showed that MBGMs exhibited good biocompatibility. The results indicated that MBGMs could be a promising candidate as a drug/protein carrier for bone tissue regeneration. (C) 2019 Published by Elsevier B.V. on behalf of The Society of Powder Technology Japan. All rights reserved.

糖尿病患者皮肤易受损伤,并因其复杂的异常病理生理学过程而愈合延迟或不愈合,降低了患者的生活质量,成为亟待解决的难点和热点.成纤维细胞(FB)是皮肤组织的重要细胞成分之一,是真皮层中分泌细胞外基质(ECM)的主要修复细胞,更是创伤愈合的关键与基础.近几年来,有关糖尿病对FB的影响以及对其改变的研究发展迅速.最新研究发现,糖尿病患者FB的改变在其创面难愈中起重要作用.该文就糖尿病创面愈合中糖尿病对FB的影响以及FB的变化作一综述,以了解其具体机制.

We prepared micro-/nano-bioactive glasses (MNBG) with controlled morphologies by using a sol-gel method combined with a template (CTAB) centered self-assembly technology, and investigated the effect of the MNBG morphology on physicochemical properties, apatite-forming ability and biocompatibility. Results showed that the specific surface area of rod-like MNBG (RBG) with highly ordered mesoporous structure was higher than that of spherical MNBG (SBG) with irregular worm-like mesoporous structure. Both the MNBG showed the high apatite-forming ability, and the apatite-forming ability of RBG with higher specific surface area was higher than that of SBG. Futhermore, both SBG and RBG had good biocompatibility, could promote proliferation and ALP differentiation of human dental pulp cells (HDPCs), and SBG with a smaller aspect ratio could significantly increase the proliferation and differentiation of the cells, as compared to RBG. This study may motivate the development and applications of MNBG with controllable morphology in dental repair. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Correction for An injectable hyaluronic acid/PEG hydrogel for cartilage tissue engineering formed by integrating enzymatic crosslinking and Diels-Alder click chemistry' by Feng Yu et al., Polym. Chem., 2014, 5, 1082-1090.

Bio-inspired pinecone-like bioactive glasses consisting of ordered thin-layers separated by consistent cavities were synthesized using a sol-gel process. The short diameter of the as-produced particles was as short as 161 nm, and the surface area was as high as 280 m2 g-1. The pore volume, ranging from ∼0.74 cm3 g-1 to ∼0.67 cm3 g-1, could be modulated by the aqueous ammonia concentration. The surface was further tailored for positive charges by amino grafting. The as-produced nanoparticles could successfully enter cells via endocytosis. The microRNA delivery of the bioactive glass particles was further investigated by fluorescence microscopy and flow cytometry, indicating a loading efficiency and transfection efficiency greater than 90%. The potential of such particles as drug carriers was also studied. CCK8, live-dead cell staining and PI/annexinV double staining analyses confirmed that the bioactive glass particles loaded with antitumour doxorubicin (DOX) significantly accelerated the apoptosis of tumour cells. These bio-inspired bioactive glasses are promising as novel vectors for drug and microRNA delivery with high efficiency.

Three-dimensional (3D) bioactive protein-patterned hydrogels provide a more biomimetic environment for cell culture than traditional bioinert scaffolds. However, it has proved difficult to obtain a hydrogel with simultaneously patterned proteins and controlled release at a later stage without inactivating the bioactivity of the fragile proteins. In this study, an aptamer-patterned PEG hydrogel was formed using biorthogonal "click chemistry". The patterned aptamer could selectively capture the bioactive protein based on the specific affinity between the aptamer and protein, which results in the formation of a patterned protein within the hydrogel. More importantly, by adding the complementary DNA strand (cDNA) of the aptamer, the protein can dissociate from the aptamer at any desired time and concentration due to the DNA hybridization. This aptamer-patterned hydrogel could become a smart and biomimetic 3D micro-environment for controlled delivery of proteins simultaneously in a spatiotemporal manner.

Dental pulp vitality is extremely important for the tooth viability, since it provides nutrition and forms the dentin. Bioactive glasses (BGs) may be promising materials for pulp repair due to their excellent abilities of rapidly bonding to bone and stimulating new bone growth. However, the unsatisfied handling property, low plasticity, and poor rapid-setting property of traditional BGs limit its application in vital pulp therapy. Spherical bioactive glasses (SBGs) exhibited higher osteogenesis and odontogenic differentiation than irregular BGs. This study focuses on the application of SBGs with rapid setting property for dental pulp repair. Here, SBGs with various compositions were successfully synthesized by a sol-gel process using dodecylamine (DDA) served as both a catalyst and a template. The maximum content of CaO in SBGs was about 15%. The non-bridge oxygen amounts of the SiO network and the apatite-forming ability increased with the content proportion of CaO and P2O5. Bioactive glass pulp capping materials (BGPCMs) were prepared by mixing the SBGs powders and the phosphate buffer solution (PBS). The K3CaH(PO4)2 and hydroxyapatite (HA) formed between SBGs particles as soon as they were mixed with PBS solution. The compressive strengths of fully set BCPCM-2 molded were measured to be 31.76±1.9577MPa after setting for 24h. The K3CaH(PO4)2 and the low crystallinity HA phases at the initial stage of solidification transformed to crystalline HA for 3days, and the compressive strength was still higher than 10MPa. Additionally, SBG-2 with a designed molar composition of 35% SiO2, 55% CaO and 10% P2O5 more promoted dental pulp cell proliferation, and could be potential pulp capping applications.

We synthetized a series of strontium-substituted submicron bioactive glasses spheres (Sr-SBG, SiO2-P2O5-CaO-SrO) in which strontium was substituted for calcium on a mole percentage basis, then investigated the effect of strontium-substituted amount on morphologies, physicochemical properties, apatite-forming bioactivity of SBG and evaluated the proliferation, differentiation and mineralization of Sr-SBG with different strontium substitution amounts by co-cultured with human dental pulp cells (HDPCs). Results showed that Sr-SBG with different strontium substitution amounts were successfully fabricated and substituting different strontium amounts did not affect the morphology and particle size of SBG. All the Sr-SBG possessed good apatite-forming ability, but substituting a certain amount of strontium for calcium would weaken the apatite-forming ability of SBG. Additionally, all the Sr-SBG extractions promoted proliferation, early odontogenic differentiation and mineralization of HDPCs, however, the cell proliferation, differentiation and mineralization abilities would be reduced when the substituted amount of strontium was excess (15 mol%). This study suggests that Sr-SBG with moderate strontium substitution amounts can be used as a more promising biomaterial for dental repair. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Mono-disperse spherical mesoporous nano- and micro- bioactive glass particles (NMBGs) can find potential use in bone tissue engineering. However, their size-dependent interaction with osteoblasts has never been studied. Herein, the proliferation, morphology, cytoskeleton organization and apoptosis of MC3T3-E1 osteoblasts are studied in response to the NMBGs with varying sizes (from 61 to 1085 nm) at different concentrations. Generally, smaller NMBGs at a lower dose show weaker cytotoxicity compared to the larger particles and higher doses, arising from a novel size-dependent mechanisrm of intracellular localization of NMBGs observed by electron and confocal microscopy. Specifically, NMBGs pass through perinuclear membrane of the cells to initiate endocytosis. Once internalized, the sizes of NMBGs are found to play a significant role in determining their intracellular localization. When the NMBGs are smaller than 174 nm, they are transported via the lysosomal pathway and phagocytized in lysosomes, resulting in little cytotoxicity at later time points. On the contrary, larger NMBGs (over 174 nm) escape from the lysosomes after endocytosis, and are localized inside the intra-cytoplasmic vacuoles or randomly in the cytoplasm of cells. Their lysosomal escape may damage the lysosomes, inducing cell apoptosis and thus the greater cytotoxicity.

Event Abstract Back to Event Research progress of micro/nano-bioactive glasses for bone and skin restoration Xiaofeng Chen1, 2, Yuli Li1, 2, Cong Mao1, 2, 3, Qing Hu1, 2, Guohou Miao1, 2, Yudong Wang1, 2, Cai Lin1, 2, 4, Yanmei Dong5 and Sainan Wang5 1 South China University of Technology, National Engineering Research Center for Tissue Restoration and Reconstruction (NERC-TRR), China 2 South China University of Technology, Key Laboratory of Biomedical Materials and Engineering of Ministry of Education, China 3 The Second Affiliated Hospital of Wenzhou Medical University, Department of Orthopedics, China 4 The First Affiliated Hospital of Wenzhou Medical University, Department of Burn, China 5 Peking University School and Hospital of Stomatology, Department of Cariology and Endodontology, China The design and development of novel cell-mediated and gene-activated bioactive materials has become one of important research fields for tissue regeneration. In this study, the new type of bioactive materials: micro-/nano-bioactive glasses (MNBG) were prepared using organic template synthesis combined with sol-gel technology. These new bioactive glasses possess high surface area, good cell compatibility, rapid bone bonding and the ability to stimulate new bone formation, enhance angiogenesis and wound healing. This research explained the detailed mechanisms on the cell-mediated and gene-activated function for osteogenesis, vascularization and wound healing related cells and genes. Firstly, when BG was co-cultured with osteoblasts, both BG contacted cells and surrounding cells experienced proliferation and differentiation, and the mRNA level of the bone healing maker such as osteocalcin, alkaline phosphatase and osteopontin were significantly up-regulated, which confirmed the gene-activated function of ionic dissolution products from bioactive glass on surrounding cells, and the gene activation effects can be directly affected by the ionic release quantity. Our study also showed that the p38 and ERK signaling pathways was activated in MSCs (mesenchymal stem cells), resulting in the directional differentiation into the osteoblasts. The released Si and Ca further promoted the expressions of the osteogenic genes and proteins, such as the Runx 2, ALP and OCN. Therefore, we concluded that the osteogenesis of BG was not only related to the fast biomineralization process, but also depended on the cell-mediated and gene-activated functions. Moreover, MNBG could activate the VEGF (vascular endothelial growth factor) signaling pathway and up-regulate the expressions of angiogenic genes and proteins such as the VEGF and VEGF receptor, resulting in the faster proliferation, migration and angiogensis of the endothelial cells. Futhermore, in vivo study showed that the TGF-β (Transforming growth factor-β) signaling pathway was also activated with the high level expression of α-SMA and collagen I genes and proteins. Those co-effects resulted in the faster and better healing process of the normal and diabetic cutaneous wounds. In conclusion, Micro-/nano-bioactive glasses could be a promissing kind of biomaterials for hard tissue repair, and cutaneous wound healing. National Program on Key Basic Research Project (grant No. 2011CB606204); National Natural Science Foundation of China (grant Nos. 51172073 and 51202069) Keywords: Bone Regeneration, nanoparticle, Bioactivity, Cell interaction Conference: 10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016. Presentation Type: Poster Topic: Biomaterials in musculoskeletal orthopeadics and tissues Citation: Chen X, Li Y, Mao C, Hu Q, Miao G, Wang Y, Lin C, Dong Y and Wang S (2016). Research progress of micro/nano-bioactive glasses for bone and skin restoration. Front. Bioeng. Biotechnol. Conference Abstract: 10th World Biomaterials Congress. doi: 10.3389/conf.FBIOE.2016.01.02594 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 27 Mar 2016; Published Online: 30 Mar 2016. Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Xiaofeng Chen Yuli Li Cong Mao Qing Hu Guohou Miao Yudong Wang Cai Lin Yanmei Dong Sainan Wang Google Xiaofeng Chen Yuli Li Cong Mao Qing Hu Guohou Miao Yudong Wang Cai Lin Yanmei Dong Sainan Wang Google Scholar Xiaofeng Chen Yuli Li Cong Mao Qing Hu Guohou Miao Yudong Wang Cai Lin Yanmei Dong Sainan Wang PubMed Xiaofeng Chen Yuli Li Cong Mao Qing Hu Guohou Miao Yudong Wang Cai Lin Yanmei Dong Sainan Wang Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.