To enhance the therapeutic efficacy of the baicalin-berberine complex(BA-BBR) in the treatment of ulcerative colitis(UC), BA-BBR nanocrystal microspheres(BA-BBR NC MS) were prepared using the dropping method. The microspheres were characterized in terms of morphology, particle size, differential scanning calorimetry(DSC), and powder X-ray diffraction(XRD). The release profiles of BA and BBR from the microspheres were measured, and the drug release mechanism was investigated. A rat model of UC was induced by 5% dextran sodium sulfate(DSS) and treated continuously for 7 days to evaluate the therapeutic effects of different formulations. The results showed that the prepared BA-BBR MS and BA-BBR NC MS were uniform gel spheres with particle sizes of(1.77±0.16) mm and(1.67±0.08) mm, respectively. After drying, the gels collapsed inward and exhibited a rough surface. During the preparation process, the BA-BBR nanocrystals(BA-BBR NC) were uniformly encapsulated within the microspheres. The release profiles of the microspheres followed a first-order kinetic model, and the 12-hour cumulative release of BA and BBR from BA-BBR NC MS was higher than that from BA-BBR MS. Compared with BA-BBR, BA-BBR NC, and BA-BBR MS, BA-BBR NC MS further alleviated UC symptoms in rats, most significantly reducing the levels of TNF-α, IL-1β, IL-6, and MPO, while increasing the level of IL-4 in colon tissues. These results indicate that BA-BBR NC MS, based on a "nano-in-micro" design, can deliver BA-BBR to the intestine and exert significant therapeutic effects in a UC rat model, suggesting it as a promising new strategy for the treatment of UC.
Animals ; Colitis, Ulcerative/metabolism* ; Rats ; Nanoparticles/chemistry* ; Microspheres ; Male ; Berberine/administration & dosage* ; Flavonoids/administration & dosage* ; Rats, Sprague-Dawley ; Drugs, Chinese Herbal/administration & dosage* ; Humans ; Particle Size ; Tumor Necrosis Factor-alpha/immunology* ; Drug Liberation ; Drug Compounding

OBJECTIVES: To fabricate an injectable composite microsphere hydrogel reinforced with silk fibroin/hyaluronic acid microspheres, achieving synergistic enhance-ment of mechanical robustness and biofunctionality. METHODS: Methacrylated hyaluronic acid (HAMA) and thiolated silk fibroin (TSF) were synthesized. Monodisperse microspheres generated via microfluidics were UV-cured (420 nm) through thiol-ene click reaction. These microspheres were embedded in a TSF/HAMA matrix to form photo-cured composites. The grafting rate of TSF and HAMA was characterized by H1-NMR; particle size distribution of microsphere hydrogels in soybean oil was observed by optical microscopy; gel point of composite microsphere hydrogels was determined by advanced extensional rheometer; microscopic morphology of microsphere hydrogels was observed by scanning electron microscopy; elemental distribution of microsphere hydrogels was detected by X-ray energy dispersive spectroscopy; tunability of composite microsphere hydrogels was observed by inverted confocal microscopy; mechanical properties of composite microsphere hydrogels were tested by compression testing; swelling ratio, degradation rate and water retention rate of composite microsphere hydrogels were measured by gravimetric method. Cytotoxicity of the composite microsphere hydrogels was determined by Calcein-AM/propidium iodide dual staining and CCK-8 assay; cell migration capability was observed by scratch assay. RESULTS: The grafting rates of HAMA and TSF was 48.03% and 17.99%, respectively. Microsphere hydrogels with particle sizes of (43.3±1.2), (78.1±3.0), and (130.8±1.9) μm were prepared. The gel time of the composite microsphere hydrogels was 48-115s. The laser confocal imaging confirmed dynamic regulation characteristics of the composite microsphere hydrogels. The compressive strength of the composite microsphere hydrogels reached 22.7 kPa and maintained structural integrity at 40% strain after 20 compression cycles. The composite microsphere hydrogels exhibited differential deswelling behaviors in simulated physiological environments, and reducing microsphere particle size could significantly enhance its stability under moist conditions. The degradation rate of the composite microsphere hydrogels was (49.1±0.9)% after 200 h, and water retention rate was maintained at 40%-60% after 96 h. Biocompatibility assays confirmed >95% cell viability and unimpaired cell migration abilities. CONCLUSIONS The TSF/HAMA composite microsphere hydrogel developed in this study has characteristics of rapid fabrication, adjustable mechanical properties, enhanced environmental stability and excellent biocom-patibility, thus providing a new material solution for tissue repair and regenerative medicine.
Fibroins/chemistry* ; Hydrogels/chemistry* ; Microspheres ; Hyaluronic Acid/chemistry* ; Humans

The structural characteristics and clinical application of embolic microspheres were summarized in this paper. According to evaluation experience and current regulatory registration evaluation requirements, registration evaluation concerns on embolic microsphere as medical device were analyzed from four aspects: administration attributes, product description, non-clinical studies and clinical evaluation, in order to provide references for the development and registration application of such products and improve the efficiency of registration application.
Microspheres ; Device Approval ; Embolization, Therapeutic/instrumentation*

One of the key components of adsorbents for blood purification is the microsphere adsorbent. Microsphere adsorbents should meet the following requirements: stable physical and chemical structures, easy for functional modification to endow the adsorbents with specific adsorption functions or characteristics, with good biocompatibility and with low non-specific adsorption, as well as with enough mechanical strength. Microsphere adsorbents prepared from polysaccharide bio-based materials fulfill the above requirements and have been widely used in the field of blood adsorption. In this article, adsorbents prepared from polysaccharide bio-based materials such as cellulose, agarose, alginate, as well as adsorbents prepared from the aforementioned materials and carbon materials and the application of the said bio-based adsorbents in blood adsorption is reviewed. The future development is also discussed, aiming to provide guidance and reference for the preparation, functional modification and application research of bio-based adsorbents for blood adsorption.
Microspheres ; Adsorption ; Humans

Regenerating periodontal bone defect surrounding periodontal tissue is crucial for orthodontic or dental implant treatment. The declined osteogenic ability of periodontal ligament stem cells (PDLSCs) induced by inflammation stimulus contributes to reduced capacity to regenerate periodontal bone, which brings about a huge challenge for treating periodontitis. Here, inspired by the adhesive property of mussels, we have created adhesive and mineralized hydrogel microspheres loaded with traditional compound cordycepin (MMS-CY). MMS-CY could adhere to the surface of alveolar bone, then promote the migration capacity of PDLSCs and thus recruit them to inflammatory periodontal tissues. Furthermore, MMS-CY rescued the impaired osteogenesis and ligament-forming capacity of PDLSCs, which were suppressed by the inflammation stimulus. Moreover, MMS-CY also displayed the excellent inhibitory effect on the osteoclastic activity. Mechanistically, MMS-CY inhibited the premature senescence induced by the inflammation stimulus through the nuclear factor erythroid 2-related factor (NRF2) pathway and reducing the DNA injury. Utilizing in vivo rat periodontitis model, MMS-CY was demonstrated to enhance the periodontal bone regeneration by improving osteogenesis and inhibiting the osteoclastic activity. Altogether, our study indicated that the multi-pronged approach is promising to promote the periodontal bone regeneration in periodontitis condition by reducing the inflammation-induced stem cell senescence and maintaining bone homeostasis.
Animals ; Bone Regeneration/drug effects* ; Rats ; Periodontal Ligament/cytology* ; Microspheres ; NF-E2-Related Factor 2 ; Hydrogels ; Periodontitis/therapy* ; Osteogenesis/drug effects* ; Disease Models, Animal ; Stem Cells ; Male ; Rats, Sprague-Dawley ; Humans

Gelatin microspheres were discussed as a scaffold material for bone tissue engineering, with the advantages of its porosity, biodegradability, biocompatibility, and biosafety highlighted. This review discusses how bone regeneration is aided by the three fundamental components of bone tissue engineering-seed cells, bioactive substances, and scaffold materials-and how gelatin microspheres can be employed for in vitro seed cell cultivation to ensure efficient expansion. This review also points out that gelatin microspheres are advantageous as drug delivery systems because of their multifunctional nature, which slows drug release and improves overall effectiveness. Although gelatin microspheres are useful for bone tissue creation, the scaffolds that take into account their porous structure and mechanical characteristics might be difficult to be created. This review then discusses typical techniques for creating gelatin microspheres, their recent application in bone tissue engineering, as well as possible future research directions.
Tissue Engineering/methods* ; Tissue Scaffolds/chemistry* ; Gelatin/chemistry* ; Microspheres ; Bone and Bones ; Porosity

Sodium alginate (SA) is a kind of natural polymer material extracted from kelp, which has excellent biocompatibility, non-toxicity, biodegradability and abundant storage capacity. The formation condition of sodium alginate gel is mild, effectively avoiding the inactivation of active substances. After a variety of preparation methods, sodium alginate microspheres are widely used in the fields of biomaterials and tissue engineering. This paper reviewed the common methods of preparing alginate microspheres, including extrusion, emulsification, electrostatic spraying, spray drying and coaxial airflow, and discussed their applications in biomedical fields such as bone repair, hemostasis and drug delivery.
Alginates ; Biocompatible Materials ; Drug Delivery Systems ; Microspheres ; Plastic Surgery Procedures

OBJECTIVE: To prepare a novel hyaluronic acid methacrylate (HAMA) hydrogel microspheres loaded polyhedral oligomeric silsesquioxane-diclofenac sodium (POSS-DS) patricles, then investigate its physicochemical characteristics and in vitro and in vivo biological properties. METHODS: Using sulfhydryl POSS (POSS-SH) as a nano-construction platform, polyethylene glycol and DS were chemically linked through the "click chemistry" method to construct functional nanoparticle POSS-DS. The composition was analyzed by nuclear magnetic resonance spectroscopy and the morphology was characterized by transmission electron microscopy. In order to achieve drug sustained release, POSS-DS was encapsulated in HAMA, and hybrid hydrogel microspheres were prepared by microfluidic technology, namely HAMA@POSS-DS. The morphology of the hybrid hydrogel microspheres was characterized by optical microscope and scanning electron microscope. The in vitro degradation and drug release efficiency were observed. Cell counting kit 8 (CCK-8) and live/dead staining were used to detect the effect on chondrocyte proliferation. Moreover, a chondrocyte inflammation model was constructed and cultured with HAMA@POSS-DS. The relevant inflammatory indicators, including collagen type Ⅱ, aggrecan (AGG), matrix metalloproteinase 13 (MMP-13), recombinant A disintegrin and metalloproteinase with thrombospondin 5 (Adamts5), and recombinant tachykinin precursor 1 (TAC1) were detected by immunofluorescence staining and real-time fluorescence quantitative PCR, with normal cultured chondrocytes and the chondrocyte inflammation model without treatment as control group and blank group respectively to further evaluate their anti-inflammatory activity. Finally, by constructing a rat model of knee osteoarthritis, the effectiveness of HAMA@POSS-DS on osteoarthritis was evaluated by X-ray film and Micro-CT examination. RESULTS: The overall particle size of POSS-DS nanoparticles was uniform with a diameter of about 100 nm. HAMA@POSS-DS hydrogel microspheres were opaque spheres with a diameter of about 100 μm and a spherical porous structure. The degradation period was 9 weeks, during which the loaded POSS-DS nanoparticles were slowly released. CCK-8 and live/dead staining showed no obvious cytotoxicity at HAMA@POSS-DS, and POSS-DS released by HAMA@POSS-DS significantly promoted cell proliferation (P<0.05). In the chondrocyte anti-inflammatory experiment, the relative expression of collagen type Ⅱ mRNA in HAMA@POSS-DS group was significantly higher than that in control group and blank group (P<0.05). The relative expression level of AGG mRNA was significantly higher than that of blank group (P<0.05). The relative expressions of MMP-13, Adamts5, and TAC1 mRNA in HAMA@POSS-DS group were significantly lower than those in blank group (P<0.05). In vivo experiments showed that the joint space width decreased after operation in rats with osteoarthritis, but HAMA@POSS-DS delayed the process of joint space narrowing and significantly improved the periarticular osteophytosis (P<0.05). CONCLUSION HAMA@POSS-DS can effectively regulate the local inflammatory microenvironment and significantly promote chondrocyte proliferation, which is conducive to promoting cartilage regeneration and repair in osteoarthritis.
Animals ; Rats ; Matrix Metalloproteinase 13 ; Microspheres ; Hydrogels ; Collagen Type II ; Diclofenac ; Inflammation ; Osteoarthritis, Knee/drug therapy* ; Hyaluronic Acid ; Aggrecans

OBJECTIVE: To construct polyhydroxyalkanoate (PHA) microspheres loaded with bone morphogenetic protein 2 (BMP-2) and human β-defensin 3 (HBD3), and evaluate the antibacterial activity of microspheres and the effect of promoting osteogenic differentiation, aiming to provide a new option of material for bone tissue engineering. METHODS: The soybean lecithin (SL)-BMP-2 and SL-HBD3 were prepared by SL-mediated introduction of growth factors into polyesters technology, and the functional microsphere (f-PMS) containing BMP-2 and HBD3 were prepared by microfluidic technology, while pure microsphere (p-PMS) was prepared by the same method as the control. The morphology of microspheres was observed by scanning electron microscopy and the water absorption was detected; the release curves of BMP-2 and HBD3 in f-PMS were detected by ELISA kit. The antibacterial effect of microspheres in Staphylococcus aureus and Escherichia coli was tested with the LIVE/DEAD^TM BacLight^TM bacterial staining kit; the biocompatibility of microspheres was tested using Transwell and cell counting kit 8 (CCK-8). The effect of microspheres on osteogenic differentiation was determined by collagen type Ⅰ (COL-1) immunofluorescence staining and alkaline phosphatase (ALP) concentration. RESULTS: In this experiment, the f-PMS and p-PMS were successfully constructed. Morphological characteristics showed that p-PMS surface was rough and distributed with micropores of 1-3 μm, while f-PMS surface was smooth and existed white granular material. There was no significant difference in water absorption between the two groups (P>0.05). The release curves of BMP-2 and HBD3 in the f-PMS and p-PMS were basically the same, showing both early sudden release and late slow release. The antibacterial activity of f-PMS was significantly higher than that of p-PMS in the test that against Staphylococcus aureus and Escherichia coli (P<0.05), but there was no significant difference in biocompatibility between the two groups (P>0.05). The results of osteogenic differentiation of human BMSCs showed that the fluorescence intensity of osteogenic specific protein COL-1 of f-PMS was significantly higher than that in p-PMS, and the activity of ALP in f-PMS was also significantly higher than that in p-PMS (P<0.05). CONCLUSION The p-PHA have good antibacterial activity and biocompatibility, and can effectively promote the osteogenic differentiation of human BMSCs, which is expected to be applied to bone tissue engineering in the future.
Humans ; Osteogenesis ; Polyhydroxyalkanoates ; Microspheres ; Alkaline Phosphatase ; Anti-Bacterial Agents/pharmacology* ; Coloring Agents ; Escherichia coli

OBJECTIVE: To develop a drug-loaded composite microsphere that can simultaneously release the berberine (BBR) and naringin (NG) to repair infectious bone defects. METHODS: The NG was loaded on mesoporous microspheres (MBG) to obtain the drug-loaded microspheres (NG-MBG). Then the dual drug-loaded compound microspheres (NG-MBG@PDA-BBR) were obtained by wrapping NG-MBG with polydopamine (PDA) and modifying the coated PDA with BBR. The composite microspheres were characterized by scanning electron microscopy, X-ray diffraction, specific surface area and pore volume analyzer, and Fourier transform infrared spectroscopy; the drug loading rate and release of NG and BBR were measured; the colony number was counted and the bacterial inhibition rate was calculated after co-culture with Staphylococcus aureus and Escherichia coli for 12 hours to observe the antibacterial effect; the biocompatibility was evaluated by live/dead cell fluorescence staining and cell counting kit 8 assay after co-culture with rat's BMSCs for 24 and 72 hours, respectively, and the osteogenic property was evaluated by alkaline phosphatase (ALP) staining and alizarin red staining after 7 and 14 days, respectively. RESULTS: NG-MBG@PDA-BBR and three control microspheres (MBG, MBG@PDA, and NG-MBG@PDA) were successfully constructed. Scanning electron microscopy showed that NG-MBG@PDA-BBR had a rough lamellar structure, while MBG had a smooth surface, and MBG@PDA and NG-MBG@PDA had a wrapped agglomeration structure. Specific surface area analysis showed that MBG had a mesoporous structure and had drug-loading potential. Low angle X-ray diffraction showed that NG was successfully loaded on MBG. The X-ray diffraction pattern contrast showed that all groups of microspheres were amorphous. Fourier transform infrared spectroscopy showed that NG and BBR peaks existed in NG-MBG@PDA-BBR. NG-MBG@PDA-BBR had good sustained drug release ability, and NG and BBR had early burst release and late sustained release. NG-MBG@PDA-BBR could inhibit the growth of Staphylococcus aureus and Escherichia coli, and the antibacterial ability was significantly higher than that of MBG, MBG@PDA, and NG-MBG@PDA ( P<0.05). But there was a significant difference in biocompatibility at 72 hours among microspheres ( P<0.05). ALP and alizarin red staining showed that the ALP positive area and the number of calcium nodules in NG-MBG@PDA-BBR were significantly higher than those of MBG and NG-MBG ( P<0.05), and there was no significant difference between NG-MBG@PDA and NG-MBG@PDA ( P>0.05). CONCLUSION NG-MBG@PDA-BBR have sustained release effects on NG and BBR, indicating that it has ideal dual performance of osteogenesis and antibacterial property.
Rats ; Animals ; Osteogenesis ; Delayed-Action Preparations/pharmacology* ; Microspheres ; Berberine/pharmacology* ; Anti-Bacterial Agents/pharmacology* ; Escherichia coli