Nanofibrous Microspheres Research Articles

Granular Porous Nanofibrous Microspheres Enhance Cellular Infiltration for Diabetic Wound Healing.

Diabetic foot ulcers (DFUs) are a significant challenge in the clinical care of diabetic patients, often necessitating limb amputation and compromising the quality of life and life expectancy of this cohort. Minimally invasive therapies, such as modular scaffolds, are at the forefront of current DFU treatment, offering an efficient approach for administering therapeutics that accelerate tissue repair and regeneration. In this study, we report a facile method for fabricating granular nanofibrous microspheres (NMs) with predesigned structures and porosities. The proposed technology combines electrospinning and electrospraying to develop a therapeutic option for DFUs. Specifically, porous NMs were constructed using electrospun poly(lactic-co-glycolic acid) (PLGA):gelatin short nanofibers, followed by gelatin cross-linking. These NMs demonstrated enhanced cell adhesion to human dermal fibroblasts (HDF) during an in vitro cytocompatibility assessment. Notably, porous NMs displayed superior performance owing to their interconnected pores compared to nonporous NMs. Cell-laden NMs demonstrated higher Young's modulus values than NMs without loaded cells, suggesting improved material resiliency attributed to the reinforcement of cells and their secreted extracellular matrix. Dynamic injection studies on cell-laden NMs further elucidated their capacity to safeguard loaded cells under pressure. In addition, porous NMs promoted host cell infiltration, neovascularization, and re-epithelialization in a diabetic mouse wound model, signifying their effectiveness in healing diabetic wounds. Taken together, porous NMs hold significant potential as minimally invasive, injectable treatments that effectively promote tissue integration and regeneration.

Nanofibrous Microspheres: A Biomimetic Platform for Bone Tissue Regeneration.

Bone, a fundamental constituent of the human body, is a vital scaffold for support, protection, and locomotion, underscoring its pivotal role in maintaining skeletal integrity and overall functionality. However, factors such as trauma, disease, or aging can compromise bone structure, necessitating effective strategies for regeneration. Traditional approaches often lack biomimetic environments conducive to efficient tissue repair. Nanofibrous microspheres (NFMS) present a promising biomimetic platform for bone regeneration by mimicking the native extracellular matrix architecture. Through optimized fabrication techniques and the incorporation of active biomolecular components, NFMS can precisely replicate the nanostructure and biochemical cues essential for osteogenesis promotion. Furthermore, NFMS exhibit versatile properties, including tunable morphology, mechanical strength, and controlled release kinetics, augmenting their suitability for tailored bone tissue engineering applications. NFMS enhance cell recruitment, attachment, and proliferation, while promoting osteogenic differentiation and mineralization, thereby accelerating bone healing. This review highlights the pivotal role of NFMS in bone tissue engineering, elucidating their design principles and key attributes. By examining recent preclinical applications, we assess their current clinical status and discuss critical considerations for potential clinical translation. This review offers crucial insights for researchers at the intersection of biomaterials and tissue engineering, highlighting developments in this expanding field.

Seafood waste derived Pt/Chitin nanocatalyst for efficient hydrogenation of nitroaromatic compounds

The fabrication of reliable, reusable and efficient catalyst is crucial for the conversion of nitroaromatic compounds into more chemically valuable amine-based molecules. In this study, a series of chitin supported platinum (Pt) catalysts with high catalytic activity, stability, and reusability were developed by using chitin derived from seafood waste as raw materials. The catalytic performance differences among these catalysts activated by different methods were investigated by hydrogenation of nitroaromatic compounds. The results showed that the multilayer hierarchical pore structure and abundance of hydroxyl and acetamido groups in chitin provided ample anchoring sites for Pt nanoparticles (NPs), ensuring the high dispersion of Pt NPs. Moreover, the interconnected channels between chitin nanofibrous microspheres facilitated rapid transport of reaction substrates. The best Pt/Chitin catalyst exhibited excellent catalytic activity and broad substrate applicability in hydrogenation of nitroaromatic compounds. Significantly, even after 20 runs, no discernible deactivation of activity was observed, demonstrating exceptional catalytic reusability. The application of seafood waste-based catalysts is conducive to the development of a green/sustainable society.

E7-Conjugated Bio-Inspired Microspheres as a Biological Barrier for Guided Tissue Regeneration.

Guided tissue regeneration (GTR), which is based on creating a physical barrier to prevent the downgrowth of epithelial and connective tissues into the defect site, has been widely used in clinical practice for periodontal regeneration for many years. However, its outcomes remain variable due to highly specific indications, the demand for proficient surgical skills, and frequent occurrence of complications. In this study, we developed a new GTR biomaterial that acts as a biological barrier for epithelial cells and fibroblasts while also serving as a scaffold for bone marrow-derived mesenchymal stem cells (BMSCs) and periodontal ligament stem cells (PDLSCs). This innovative GTR biomaterial is bioinspired injectable microspheres that are self-assembled from nanofibers, and their surfaces are conjugated with E7, a short peptide that selectively promotes BMSC and PDLSC adhesion but inhibits the attachment and spreading of epithelial cells and gingival fibroblasts. The selective affinity afforded by E7 on the surfaces of the nanofibrous microspheres facilitated the colonization of BMSCs in the periodontal defect, thereby substantially improving functional periodontal regeneration, as evidenced by enhanced new bone formation, reduced root exposure, and diminished attachment loss. The remarkable superiority of the bioinspired microspheres over conventional GTR materials in promoting periodontal regeneration underscores the potential of this innovative approach to enhance the efficacy of functional periodontal tissue regeneration.

Facile synthesis of FeF3•0.33H2O@3D N-doped carbon microspheres via self-assembly: An examination of electrochemical cathode dynamics in lithium-ion batteries

The theoretical capacity of FeF3 is 712 mAh g−1, making it a potential candidate as the next-generation cathode material of lithium-ion battery. However, FeF3 suffers from poor electronic/ion conductivity and poor kinetics. In this study, FeF3⋅0·33H2O@3D N-doped carbon nanofibrous microspheres (referred to as FF@CM) were prepared by EDTA self-assembly with chitosan fibers/Fe3+ sources, then carbonization and in-situ fluorination. The ultrafine FeF3⋅0.33H2O nanoparticles with an average diameter of 4.42 nm were found embedded in the 3D N-doped carbon microspheres. The FF@CM cathode delivers an initial discharge capacity of 353.57 mAh g−1 at 0.2C with a capacity decay rate of 6.77 % after 25 cycles, outperforming the bare FF cathode (with an initial discharge capacity of 263.92 mAh g−1 and a capacity decay rate of 35.95 %), the reversible capacities of the FF@CM and bare FF electrodes after 200 cycles at 0.2C are 96.29 and 4.75 mAh g−1, the pseudocapacitive contribution is up to 64 % for the FF@CM cathode at 1.0 mV s−1. The specific discharge capacities of FF@CM at 0.1, 0.2, 0.5, and 1C were 477.57, 432.15, 309.87 and 233.37 mAh g−1. Upon returning the rate to 0.1C, FF@CM recovered to the 79.23 % of the original capacity. The excellent electrochemical dynamics are attributed to its better electrolyte wettability and electronic conductivity of 3D porous microspheres, which have key contributions to advanced pseudo-capacitive behavior.

Bioinspired 3D-printed scaffold embedding DDAB-nano ZnO/nanofibrous microspheres for regenerative diabetic wound healing

There is a constant demand for novel materials/biomedical devices to accelerate the healing of hard-to-heal wounds. Herein, an innovative 3D-printed bioinspired construct was developed as an antibacterial/regenerative scaffold for diabetic wound healing. Hyaluronic/chitosan (HA/CS) ink was used to fabricate a bilayer scaffold comprising a dense plain hydrogel layer topping an antibacterial/regenerative nanofibrous layer obtained by incorporating the hydrogel with polylactic acid nanofibrous microspheres (MS). These were embedded with nano ZnO (ZNP) or didecyldimethylammonium bromide (DDAB)-treated ZNP (D-ZNP) to generate the antibacterial/healing nano/micro hybrid biomaterials, Z-MS@scaffold and DZ-MS@scaffold. Plain and composite scaffolds incorporating blank MS (blank MS@scaffold) or MS-free ZNP@scaffold and D-ZNP@scaffold were used for comparison. 3D printed bilayer constructs with customizable porosity were obtained as verified by SEM. The DZ-MS@scaffold exhibited the largest total pore area as well as the highest water-uptake capacity and in vitro antibacterial activity. Treatment of Staphylococcus aureus-infected full thickness diabetic wounds in rats indicated superiority of DZ-MS@scaffold as evidenced by multiple assessments. The scaffold afforded 95% wound-closure, infection suppression, effective regulation of healing-associated biomarkers as well as regeneration of skin structure in 14 d. On the other hand, healing of non-diabetic acute wounds was effectively accelerated by the simpler less porous Z-MS@scaffold. Information is provided for the first-time on the 3D printing of nanofibrous scaffolds using non-electrospun injectable bioactive nano/micro particulate constructs, an innovative ZNP-functionalized 3D-printed formulation and the distinct bioactivity of D-ZNP as a powerful antibacterial/wound healing promotor. In addition, findings underscored the crucial role of nanofibrous-MS carrier in enhancing the physicochemical, antibacterial, and wound regenerative properties of DDAB-nano ZnO. In conclusion, innovative 3D-printed DZ-MS@scaffold merging the MS-boosted multiple functionalities of ZNP and DDAB, the structural characteristics of nanofibrous MS in addition to those of the 3D-printed bilayer scaffold, provide a versatile bioactive material platform for diabetic wound healing and other biomedical applications.

Functional microspheres for tissue regeneration.

As a new type of injectable biomaterials, functional microspheres have attracted increasing attention in tissue regeneration because they possess some advantageous properties compared to other biomaterials, including hydrogels. A variety of bio-inspired microspheres with unique structures and properties have been developed as cellular carriers and drug delivery vehicles in recent years. In this review, we provide a comprehensive summary of the progress of functional and biodegradable microspheres that have been used for tissue regeneration over the last two decades. First, we briefly introduce the biomaterials and general methods for microsphere fabrication. Next, we focus on the newly developed technologies for preparing functional microspheres, including macroporous microspheres, nanofibrous microspheres, hollow microspheres, core-shell structured microspheres, and surface-modified functional microspheres. After that, we discuss the application of functional microspheres for tissue regeneration, specifically for bone, cartilage, dental, neural, cardiac, and skin tissue regeneration. Last, we present our perspectives and future directions of functional microspheres as injectable carriers for the future advancement of tissue regeneration.

Composite PLLA/Ag@SiO2 microspheres for bone regeneration in infected bone defects

Repairing bone defects is particularly challenging when an infection is presented. In this study, poly(L-lactic) (PLLA) nanofibrous microspheres (large microspheres) were used as cell carriers to simulate the nanofibrous structure of the extracellular matrix. A planet-satellite composite microsphere with large microspheres and small microspheres was constructed by bonding hollow Ag@SiO2 nanospheres (small microspheres) to nanofibrous PLLA microspheres. According to the results, PLLA nanofibrous microspheres activated by EDC and NHS can firmly combine with Ag@SiO2 nanospheres. The composite microspheres demonstrated excellent drug release functions, antibacterial properties, and biocompatibility and promoted cell adhesion and differentiation in vitro. The bone repair function of composite microspheres loaded with BMP2 growth factor was evaluated in rat that were infected with bacteria and exhibited skull defects. A four-week study showed that these microspheres significantly promoted bone regeneration in infected bone. These multifunctional microspheres could revolutionize bone repair and provide a much-needed solution for those suffering from infected bone defects.

Nano zinc oxide-functionalized nanofibrous microspheres: A bioactive hybrid platform with antimicrobial, regenerative and hemostatic activities

Bioactive hybrid constructs are at the cutting edge of innovative biomaterials. PLA nanofibrous microspheres (NF-MS) were functionalized with zinc oxide nanoparticles (nZnO) and DDAB-modified nZnO (D-nZnO) for developing inorganic/nano-microparticulate hybrid constructs (nZnO@NF-MS and D-nZnO@NF-MS) merging antibacterial, regenerative, and haemostatic functionalities. The hybrids appeared as three-dimensional NF-MS frameworks made-up entirely of interconnecting nanofibers embedding nZnO or D-nZnO. Both systems achieved faster release of Zn2+ than their respective nanoparticles and D-nZnO@NF-MS exhibited significantly greater surface wettability than nZnO@NF-MS. Regarding bioactivity, D-nZnO@NF-MS displayed a significantly greater and fast-killing effect against Staphylococcus aureus. Both nZnO@NF-MS and D-nZnO@NF-MS showed controllable concentration-dependent cytotoxicity to human gingival fibroblasts (HGF) compared with pristine NF-MS. They were also more effective than pristine NF-MS in promoting migration of human gingival fibroblasts (HGF) in the in vitro wound healing assay. Although D-nZnO@NF-MS showed greater in vitro hemostatic activity than nZnO@NF-MS (blood-clotting index 22.82 ± 0.65% vs.54.67 ± 2.32%), both structures exhibited instant hemostasis (0 s) with no blood loss (0 mg) in the rat-tail cutting technique. By merging the multiple therapeutic bioactivities of D-nZnO and the 3D-structural properties of NF-MS, the innovative D-nZnO@NF-MS hybrid construct provides a versatile bioactive material platform for different biomedical applications.

Injectable nanofiber microspheres modified with metal phenolic networks for effective osteoarthritis treatment.

Osteoarthritis (OA) is one of the most common chronic musculoskeletal diseases, which accounts for a large proportion of physical disabilities worldwide. Herein, we fabricated injectable gelatin/poly(L-lactide)-based nanofibrous microspheres (MS) via electrospraying technology, which were further modified with tannic acid (TA) named as TMS or metal phenolic networks (MPNs) consisting of TA and strontium ions (Sr2+) and named as TSMS to enhance their bioactivity for OA therapy. The TA-modified microspheres exhibited stable porous structure and anti-oxidative activity. Notably, TSMS showed a sustained release of TA as compared to TMS, which exhibited a burst release of TA. While all types of microspheres exhibited good cytocompatibility, TSMS displayed good anti-inflammatory properties with higher cell viability and cartilage-related extracellular matrix (ECM) secretion. The TSMS microspheres also showed less apoptosis of chondrocytes in the hydrogen peroxide (H2O2)-induced inflammatory environment. The TSMS also inhibited the degradation of cartilage along with the considerable repair outcome in the papain-induced OA rabbit model in vivo as well as suppressed the expression level of inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1-beta (IL-1β). Taken together, TSMS may provide a highly desirable therapeutic option for intra-articular treatment of OA. STATEMENT OF SIGNIFICANCE: Osteoarthritis (OA) is a chronic disease, which is caused by the inflammation of joint. Current treatments for OA achieve pain relief but hardly prevent or slow down the disease progression. Microspheres are at the forefront of drug delivery and tissue engineering applications, which can also be minimal-invasively injected into the joint. Polyphenols and therapeutic ions have been shown to be beneficial for the treatment of diseases related to the joints, including OA. Herein, we prepared gelatin/poly(L-lactide)-based nanofibrous microspheres (MS) via electrospinning incorporated electrospraying technology and functionalized them with the metal phenolic networks (MPNs) consisting of TA and strontium ions (Sr2+), and assessed their potential for OA therapy both in vitro and in vivo.

Development of magnetic poly(L-lactic Acid) nanofibrous microspheres for transporting and delivering targeted cells

To avoid infection and other risks caused by large open-surgery incisions using scaffold transplants, it is very important to study injectable microcarrier-loaded cells for targeted therapy and tissue regeneration. In this study, on the one hand, to simulate the hierarchical structure of the extracellular matrix and carry cells, poly(L-lactic acid) (PLLA) nanofibrous microspheres (large microspheres) were initially fabricated as cell carriers. On the other hand, to precisely deliver cells through a magnetic field and promote stem cell differentiation, drug-loaded mesoporous Fe3O4@SiO2 microspheres (small microspheres) were prepared and coated on the surface PLLA nanofibrous microspheres. The coating conditions were systematically studied and optimized. The results showed that planetary-satellite-like cell carriers were successfully prepared and the carriers were capable of freely translocating under the influence of a magnetic field. It has been demonstrated in vitro experiments that the carriers are biocompatible and are capable of acting as drug carriers. Specifically, they were able to load and release cells in response to magnetic fields. In vivo experiments indicated that the carriers could successfully load and release GFP-labelled cells in nude mice. The study presented in this paper provides a versatile and promising platform for the cell-based therapy in tissue engineering and regenerative medicine.

Laponite–Gelatin Nanofibrous Microsphere Promoting Human Dental Follicle Stem Cells Attachment and Osteogenic Differentiation for Noninvasive Stem Cell Transplantation

Back Cover: Nanofibrous architecture of 3-dimensional scaffold can be an exceptional candidate for cell delivery. In article number 2200347, Jyotsnendu Giri and co-workers fabricated the laponite loaded osteoinductive nanofibrous microspheres to mimic the native stem cell niche. Osteoinductive nanofibrous microspheres, facilitate the excellent stem cell attachment, proliferation, and osteogenic differentiation for noninvasive stem cell transplantation.

Laponite-Gelatin Nanofibrous Microsphere Promoting Human Dental Follicle Stem Cells Attachment and Osteogenic Differentiation for Noninvasive Stem Cell Transplantation.

Nanofibrous microspheres (NFM) are emerging as prominent next-generation biomimetic injectable scaffold system for stem cell delivery and different tissue regeneration where nanofibrous topography facilitates ECM-like stem cells niches. Addition of osteogenic bioactive nanosilicate platelets within NFM can provide osteoconductive cues to facilitate matrix mediated osteogenic differentiation of stem cells and enhance the efficiency of bone tissue regeneration. In this study, gelatin nanofibrous microspheres are prepared containing fluoride-doped laponite XL21 (LP) using the emulsion mediated thermal induce phase separation (TIPS) technique. Systematic studies are performed to understand the effect of physicochemical properties of biomimicking NFM alone and with different concentrations of LP on human dental follicle stem cells (hDFSCs), their cellular attachment, proliferation, and osteogenic differentiation. The study highlights the effect of LP nanosilicate with biomimicking nanofibrous injectable scaffold system aiding in enhancing stem cell differentiation under normal physiological conditions compared to NFM without LP. The laponite-NFM shows suitability as excellent injectable biomaterials system for stem cell attachment, proliferation and osteogenic differentiation for stem cell transplantation and bone tissue regeneration.

Fabrication of Biomass Derived Pt-Ni Bimetallic Catalyst and Its Selective Hydrogenation for 4-Nitrostyrene.

The hydrogenation products of aromatic molecules with reducible groups (such as C=C, NO2, C=O, etc.) are relatively critical intermediate compounds in fine chemicals, but how to accurately reduce only specific groups is still challenging. In this work, a bimetallic Pt-Ni/Chitin catalyst was prepared for the first time by using renewable biomass resource chitin as support. As the carrier, the chitin was constructed into porous nanofibrous microspheres through the sol-gel strategy, which was favorable for the adhesion of nano-metals and the exchange of reactive substances due to its large surface area, porous structure, and rich functional groups. Then the Pt-Ni/Chitin catalyst was applied to selective hydrogenation with the model substrate of 4-nitrostyrene. As the highly dispersed Pt-Ni NPs with abundant exposed active sites and the synergistic effect of bimetals, the Pt-Ni/Chitin catalyst could efficiently and selectively hydrogenate only NO2 or C=C with yields of ~99% and TOF of 660 h−1, as well as good stability. This utilization of biomass resources to build catalyst materials would be important for the green and sustainable chemistry.

Biomimetic Natural Silk Nanofibrous Microspheres for Multifunctional Biomedical Applications.

Silk nanofibrils (SNFs) extracted from natural silkworm silk represent a class of high-potential protein nanofiber material with unexplored biomedical applications. In this study, a SNF-assembled microsphere with extracellular matrix (ECM)-mimicking architecture and high specific surface area was developed. The SNFs were exfoliated from silkworm silks through an all-aqueous process and used as the building blocks for constructing the microspheres. Inspired by the structure and bioactive composition of ECM, hyaluronic acid (HA) was used as a bio-glue to regulate SNF assembly. With the assistance of HA, the SNF microspheres with stable fluffy nanofibrous structures were synthesized through electrospray. The biomimetic structure and nature derived composition endow the microspheres with excellent biocompatibility and enhanced osteogenic differentiation-inducing ability to mesenchymal stem cells. As proof of versatility, the SNF microspheres were further functionalized with other molecules and nanomaterials. Taking the advantages of the excellent blood compatibility and modifiability from the molecular level to the nanoscale of SNF microspheres, we demonstrated their versatile applications in protease detection and blood purification. On the basis of these results, we foresee that this natural silk-based nanofibrous microsphere may serve as a superior biomedical material for tissue engineering, early disease diagnosis, and therapeutic devices.

Blood compatible chitin composite nanofibrous microspheres as efficient adsorbents for removal of blood ammonia in hyperammonemia

Ammonia is a neurotoxin that can lead to significant and permanent neurological impairment. The accumulation of ammonia in the blood of patients with liver failure can cause life-threatening hepatic encephalopathy. However, until now, there has been a lack of efficient, safe, and specific adsorbents to remove ammonia from the blood of patients with liver failure. In this study, chitin/zeolite composite nanofibrous microspheres (CZ) were prepared and evaluated as safe, efficient, and specific blood ammonia sorbents to remove ammonia from hyperammonemia plasma for the treatment of hyperammonemia. The CZ microspheres were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, physical adsorption of N2, scanning electron microscopy, transmission electron microscopy, and energy dispersive spectroscopy. CZ consists of intertwined nanofibrous network microspheres constructed from chitin nanofibers and embedded zeolite. In the in vitro adsorption experiment, CZ exhibited rapid and good affinity for ammonia in both aqueous solution and hyperammonemia plasma. The adsorption capacity of CZ2 in aqueous solution was 17.673 mg/g, which is similar to that of zeolite. The level of blood ammonia in the hyperammonemia plasma decreased from 650 to 386 μmol/L after adsorption by CZ2. In addition, CZ has been demonstrated to have good compatibility with cells and blood components (such as erythrocytes, clotting factors, and proteins), exhibiting good biocompatibility and blood compatibility. All these meet the necessary requirements for the clinical use of blood ammonia adsorbents for blood purification. Therefore, CZ has potential applications in the ammonia-induced treatment of complications.

Biomimicking nanofibrous gelatin microspheres recreating the stem cell niche for their ex-vivo expansion and in-vivo like differentiation for injectable stem cell transplantation.

Stem cells based novel treatment modality for degenerative and immune dysfunction diseases created a huge demand of suitable carriers to support ex-vivo production of quality stem cells, and effective in-vivo transplantation of stem cells and their fate. In spite of promising candidature of nanofibrous microspheres (NFM) to recreate native stem cell niches to be used for possible scaling-up for ex-vivo stem cells expansion, it remains fairly unexplored. A systematic study on the stem cell-NFM interaction comparative with commercial microspheres (CM) has been performed for the first time. Gelatin NFM with variable physicochemical properties such as size, surface properties, surface chemistry, and variable degradability were prepared using microemulsion coupled with thermally induced phase separation (TIPS) method. Effect of physicochemical properties of NFM and their cellular interaction such as binding, morphology, metabolic activity and proliferation studies were performed using human bone marrow-derived mesenchymal stem cells (hBMSCs), human dental follicle stem cells (hDFSCs) and human gingival fibroblast (HGF) cells and compared with the commercial and solid microspheres. Gelatin NFM supports excellent cell binding, proliferation, metabolic activities and chemical cues specific differentiation. All out-turns indicate that NFM stand to be an outstanding candidate for ex-vivo cells' expansion and injectable carriers for stem cell transplantation.

Surface imprinted magnetic carbon nanofibrous microspheres with hierarchical porosity for the highly efficient and selective extraction of Brilliant Blue from food samples

In this study, magnetic porous carbon microsphere composed of molecularly imprinted nanofibers (MPCM@MINs) were constructed and used as an adsorbent for the highly efficient extraction of Brilliant Blue (BB) in food samples. The MPCM@MINs contained imprinted nanofibers and a three-dimensional hierarchical porous structure with a magnetic responsive ability, resulting in a high surface area (368.3 m2·g−1), low mass-transfer resistance, large adsorption capacity, and fast separation ability. The maximum adsorption capacity of MPCM@MINs for BB was 39.47 mg·g−1 with excellent selectivity and a high imprinting factor (6.12). Moreover, MPCM@MINs exhibited good anti-interference ability, reusability and reliability. Importantly, BB can be easily and rapidly detected in food samples using MPCM@MINs as an adsorbent followed with UV–Vis method, and the relative standard deviation was lower than 5.85%. Therefore, MPCM@MINs may be a promising adsorbent for pollutant extraction in food samples due to the combination of different strategies of nanofibrous imprinting, magnetic separation, and hierarchical porous structure.

Preparation of drug loading nanofibrous microsphere scaffolds modified by ethanolamine-modified polylactide

The ethanolamine-modified polylactide (ETA-PLLA) nanofibrous microsphere was fabricated by emulsification combine with a thermally induced phase separation method. The drug loading density of loxoprofen Sodium was 11.5%, the drug loading density of ibuprofen was 2.25%, which should be attributed to the hydrophilic of ETA-PLLA. The nanofibrous injectable microspheres have a slow release effect with the loxoprofen sodium, it can prolong the time of the action of drugs in the body, reduce the side effects of drugs. It indicated that the microspheres can be used for drug loading, and it is also expected to be used for cell carriers.

Facile Construction of a Highly Dispersed Pt Nanocatalyst Anchored on Biomass-Derived N/O-Doped Carbon Nanofibrous Microspheres and Its Catalytic Hydrogenation.

With the depletion of nonrenewable resources and the increasingly serious "white pollution" caused by nondegradable plastics, using renewable biomass resources such as chitin to fabricate materials is a green and sustainable pathway. Herein, for the first time, we used N/O-doped carbon nanofibrous microspheres (CNMs) derived from renewable chitin as carriers to successfully construct a highly dispersed platinum nanocatalyst via a facile way. Various physicochemical characterizations provided reliable evidence for the ultrafine and well-dispersed platinum nanoparticles with an average diameter of 2.3 nm. As the supporting framework, the CNM with interconnected nanofibrous networks and a large surface area facilitated the adhesion and dispersion of Pt particles. Meanwhile, the inherent N/O-containing functional groups and the defects in carbonized chitin could anchor the platinum tightly. The CNM/Pt catalyst was further examined for hydrogenation, and it exhibited promising catalytic activity and stability (∼5 runs, 91%) and a broad applicability. This utilization of biomass resources to build catalyst materials would be important for the green and sustainable chemistry.