Abalone shell-derived Mg-doped mesoporous hydroxyapatite microsphere drug delivery system loaded with icariin for inducing apoptosis of osteosarcoma cells

Hydroxyapatite(HAP)porous microspheres with very high specific surface area and drug loading capacity,as well as excellent biocompatibility,have been widely used in tumour therapy.Mg^(2+)is considered to be a key factor in bone regeneration,acting as an active agent to stimulate bone and cartilage formation,and is effective in accelerating cell migration and promoting angiogenesis,which is essential for bone tissue repair,anti-cancer,and anti-infection.In this study,abalone shells from a variety of sources were used as raw materials,and Mg^(2+)-doped abalone shell-derived mesoporous HAP microspheres(Mg-HAP)were prepared by hydrothermal synthesis as Mg^(2+)/icariin smart dual delivery system(ICA-Mg-HAP,IMHA).With increasing of Mg^(2+)doping,the surface morphology of HAP microspheres varied from collapsed macroporous to mesoporous to smooth and non-porous,which may be due to Mg^(2+)substitution or coordination in the HAP lattice.At 30%Mg^(2+)doping,the Mg-HAP microspheres showed a more homogeneous mesoporous morphology with a high specific surface area(186.06 m^(2)/g).The IMHA microspheres showed high drug loading(7.69%)and encapsulation rate(83.29%),sustained Mg^(2+)release for more than 27 days,sustained and stable release of icariin for 60 hours,and good responsiveness to pH(pH 6.4>pH 5.6).In addition,the IMHA delivery system stimulated the rapid proliferation of bone marrow mesenchymal stem cells and induced apoptosis in MG63 cells by blocking the G2 phase cycle of osteosarcoma cells and stimulating the high expression of apoptotic genes(Bcl-2,caspase-3,-8,-9).This suggests that the abalone shell-based IMHA may have potential applications in drug delivery and tumour therapy.

Nanoengineered hydrogels as 3D biomimetic extracellular matrix with injectable and sustained delivery capability for cartilage regeneration

The regeneration of articular cartilage remains a great challenge due to the difficulty in effectively enhancing spontaneous healing.Recently,the combination of implanted stem cells,suitable biomaterials and bioactive molecules has attracted attention for tissue regeneration.In this study,a novel injectable nanocomposite was rationally designed as a sustained release platform for enhanced cartilage regeneration through integration of a chitosan-based hydrogel,articular cartilage stem cells(ACSCs)and mesoporous SiO_(2)nanoparticles loaded with anhydroicaritin(AHI).The biocompatible engineered nanocomposite acting as a novel 3D biomimetic extracellular matrix exhibited a remarkable sustained release effect due to the synergistic regulation of the organic hydrogel framework and mesopore channels of inorganic mSiO_(2)nanoparticles(mSiO_(2)NPs).Histological assessment and biomechanical tests showed that the nanocomposites exhibited superior performance in inducing ACSCs proliferation and differentiation in vitro and promoting extracellular matrix(ECM)production and cartilage regeneration in vivo.Such a novel multifunctional biocompatible platform was demonstrated to significantly enhance cartilage regeneration based on the sustained release of AHI,an efficient bioactive natural small molecule for ACSCs chondrogenesis,within the hybrid matrix of hydrogel and mSiO_(2)NPs.Hence,the injectable nanocomposite holds great promise for use as a 3D biomimetic extracellular matrix for tissue regeneration in clinical diagnostics.

Real-time monitoring flexible hydrogels based on dual physically cross-linked network for promoting wound healing

To achieve smart and personalized medicine, the development of hydrogel dressings with sensing properties and biotherapeutic properties that can act as a sensor to monitor of human health in real-time while speeding up wound healing face great challenge. In the present study, a biocompatible dual-network composite hydrogel(DNCGel) sensor was obtained via a simple process. The dual network hydrogel is constructed by the interpenetration of a flexible network formed of poly(vinyl alcohol)(PVA) physical cross-linked by repeated freeze-thawing and a rigid network of iron-chelated xanthan gum(XG) impregnated with Fe^(3+) interpenetration. The pure PVA/XG hydrogels were chelated with ferric ions by immersion to improve the gel strength(compressive modulus and tensile modulus can reach up to 0.62 MPa and0.079 MPa, respectively), conductivity(conductivity values ranging from 9 × 10^(-4) S/cm to 1 × 10^(-3)S/cm)and bacterial inhibition properties(up to 98.56%). Subsequently, the effects of the ratio of PVA and XG and the immersion time of Fe^(3+) on the hydrogels were investigated, and DNGel3 was given the most priority on a comprehensive consideration. It was demonstrated that the DNCGel exhibit good biocompatibility in vitro, effectively facilitate wound healing in vivo(up to 97.8% healing rate) under electrical stimulation, and monitors human movement in real time. This work provides a novel avenue to explore multifunctional intelligent hydrogels that hold great promise in biomedical fields such as smart wound dressings and flexible wearable sensors.

Versatile core-shell magnetic fluorescent mesoporous microspheres for multilevel latent fingerprints magneto-optic information recognition

Latent fingerprints are extremely vital for personal identification and criminalinvestigation,and potential information recognition techniques have been widelyused in the fields of information and communication electronics.Although physicalpowder dusting methods have been frequently employed to develop latent fingerprintsand most of them are carried out by using single component powders ofmicron-sized fluorescent particles,magnetic powders,or metal particles,there isstill an enormous challenge in producing high-resolution image of latent fingerprintsat different backgrounds or substrates.Herein,a novel and effectivenanoimpregnation method is developed to synthesize bifunctional magnetic fluorescentmesoporous microspheres for latent fingerprints visualization by growthof mesoporous silica(mesoSiO_(2))on magical Fe_(3)O_(4) core and then deposition offluorescent YVO4:Eu^(3+)nanoparticles in the mesopores.The obtainedFe_(3)O_(4)@mesoSiO_(2)@YVO4:Eu^(3+)microspheres possess spatially isolated magneticcore and fluorescent shell which were insulated by mesoporous silica layer.Dueto their small particle size of submicrometer scale,high magnetization and lowmagnetic remanence as well as the combined magnetic and fluorescent properties,the microspheres show superior performance in visual latent fingerprint recognitionwith high contrast,high anti-interference,and sensitivity as well as goodretention on multifarious substrates regardless of surface permeability,roughness,refraction,colorfulness,and background fluorescence interference,and it makesthem ideal candidates for practical application in fingerprint visualization andeven magneto-optic information storage.

One-dimensional nanochains consisting of magnetic core and mesoporous aluminosilicate for use as efficient nanocatalysts

Magnetic assembly at the nanoscale level brings potential possibilities in obtaining novel delicate nanostructures with unique physical, photonic or electronic properties. Interface surfactant micelle-directed assembly strategy holds great promising in fabricating ordered mesoporous materials with multifunctionality and pore parameter tunability. Combing these, herein, one-dimensional (1D) nanochains with well-aligned silica-coated magnetic particles as core and mesoporous aluminosilicate as shell are rational fabricated for the first time through magnetic field induced interface coassembly in biliquid system followed by the incorporation of Al species via in-situ chemical modification and transformation strategy. The obtained magnetic mesoporous aluminosilicate nanochains (MMAS-NCs) possess well-defined core-shell-shell sandwich nanostructure, tunable perpendicular mesopore channels in the shell (2.7–7.6 nm), high surface area (359 m^(2)·g^(-1)), abundant acidic sites, and superparamagnetism with a magnetization saturation of 13.8 emu·g^(-1). Thanks to the unique properties, the MMAS-NCs exhibit excellent performance in acting as magnetically recyclable superior solid acid catalysts and nanostirrers with high conversion of over 96.8%, selectivity of 95.0% in the deprotection reaction of benzaldehyde dimethylacetal to benzaldehyde. Moreover, MMAS-NCs exhibit an interesting pore size effect on the catalytic activity, namely, in the pore size range of 2–8 nm, the catalysts with larger pores show significantly enhanced catalytic activity due to the balanced mass transport and density of surface active sites.

A fast on-demand preparation of injectable self-healing nanocomposite hydrogels for efficient osteoinduction

Injectable hydrogels have been considered as promising materials for bone regeneration,but their osteoinduction and mechanical performance are yet to be improved.In this study,a novel biocompatible injectable and self-healing nano hybrid hydrogel was on-demand prepared via a fast(within 30 s)and easy gelation approach by reversible Schiff base formed between-CH=O of oxidized sodium alginate(OSA)and-NH2 of glycol chitosan(GCS)mixed with calcium phosphate nanoparticles(CaP NPs).Its raw materials can be ready in large quantities by a simple synthesis process.The mechanical strength,degradation and swelling behavior of the hydrogel can be readily controlled by simply controlling the molar ratio of-CH=O and-NH2.This hydrogel exhibits pH responsiveness,good degradability and biocompatibility.The hydrogel used as the matrix for mesenchymal stem cells can significantly induce the proliferation,differentiation and osteoinduction in vitro.These results showed this novel hydrogel is an ideal candidate for applications in bone tissue regeneration and drug delivery.