Alum has an excellent safety record and is the only licensed inorganic adjuvant for human vaccines. However, the exploration of alum nanosheets as chemotherapy drug delivery system, especially the clarification about the relationship between structures and drug loading properties, is totally insufficient. Herein, aluminum hydroxides (AlOOH) nanosheets with tunable specific surface area and pore size were synthesized by adjusting the synthesis time in the presence of triblock copolymers. The obtained materials exhibited the highest surface area about 470 m ²/g. The structure-dependent chemotherapy drug loading capability for AlOOH nanosheets was observed: the higher specific surface area and pore size are, the higher amount of chemotherapy drug is loaded. AlOOH nanosheets loaded with doxorubicin showed a pH-dependent sustained release behavior with quick release in low pH about 5 and slow release in pH around 7.4. Doxorubicin-loaded AlOOH nanosheets exhibited much higher cancer cellular uptake efficiency than that in free form by flow cytometry. Moreover, doxorubicin-loaded AlOOH nanosheets with high specific surface area showed an increased cellular uptake efficiency and enhanced ratios of apoptosis and necrosis, compared with those showing low specific surface area. Therefore, AlOOH nanosheets are promising materials as chemotherapy drug delivery system.

Aspirin/layered double hydroxides composite (A-LDHs) and aspirin/layered double hydroxide-nanosheets composite (A-LDHs-NS) were prepared by intercalation and exfoliation-recombination, respectively. Their morphology, drug loading property and drug loading mode of the composites were characterized by XRD, SEM, TG-DTG, and FT-IR. The releasing performances of aspirin from A-LDHs and A-LDHs-NS in the phosphate buffer solutions with different pH conditions were investigated. The results show that the typical lamellar structures are hold in as-prepared LDHs and LDHs-NS. The larger specific surface area (187 m ²·g ^-1) of LDHs-NS, the more aspirins are loaded on its surface, among which the max drug loading is 1.178 mmol·g ^-1. Its releasing process lasts for more than 1440 min, much longer than 20 min of the control materials, showing excellent sustained-releasing performance. This performance may because of the strong interaction between aspirin and LDHs-NS. Moreover, the sustained releasing performance is stronger at pH 7.4 than that at pH 4.8. All data from this study provides a reference for wider application of this kind of two-dimensional materials in biomedicine.

Titanate nanofibers were prepared on titanium mesh by alkali-heat treatment, and calcium phosphate coating was fabricated on the porous titanate nanofibers by electrochemical deposition technology. Then hBMP-2 was introduced into the coating by different methods to improve its osteointegration and bioactivity. Three kinds of composite coatings modified by hBMP-2 were prepared (TmhB, TmHedhB and TmHhBed). Surface morphology, chemical composition, phase composition and hBMP-2 amounts and hBMP-2 release performance of the composite coatings were characterized by SEM, ATR-FTIR, XRD, and hBMP-2 ELISA kit, respectively. Results showed that all of the coatings display porous fiber structure, calcium phosphate phase in TmHedhB and TmHhBed samples was hydroxyapatite (HA), and bead-like HA particles formed on the surface of titanate nanofibers. Protein adsorption experiments showed that introduction of bead-like HA phase increased the hBMP-2 adsorption on the composite coatings, and composite coatings prepared by electrochemical co-deposition technique further enhanced hBMP-2 adsorption up to 886 ng/mg, which were supported hBMP-2 sustained release within 6-48 h.

To prevent potassium diformate (KDF) from decomposing too quickly in an acidic environment, adjust the acidity and alkalinity of the gastrointestinal tract of the piglets and the colony balance, and realize the targeted release of KDF antibacterial, in this study, a kind of hydrogel microspheres were prepared by biodegradable chitosan (CS), carboxymethyl cellulose (CMC), and inorganic rigid material P-type molecular sieve (Zeolite P). Then the antibacterial drug potassium diformate was loaded so as to be controlled to release from this hydrogel microsphere. The results show that -NH₂ in CS and -COOH in CMC form a stable polyelectrolyte complex through ion interaction. Swelling rate test indicates that the CS/CMC/Zeolite P hydrogel microspheres display high pH-sensitivity. The addition of Zeolite P allows the hydrogel microspheres to maintain their original morphology at pH1.2 without being degraded or broken. The effective sustained-release KDF in pH7.4 phosphate buffer solution exhibits better sustained-release performance than that in pH1.2. When the concentration of CS/CMC/Zeolite P/KDF antimicrobial microspheres is 96 mg/mL, the maximum bacteriostatic rate of Escherichia coli is 83%, which effectively improves the utilization rate of KDF.

Electrospun scaffolds have been widely used in tissue engineering, particularly, bioceramics such as calcium silicate (CSH) composite electrospun scaffolds have shown excellent bioactivity by releasing SiO₃^2- ions during the degradation of calcium silicate in composite electrospun scaffolds, which are bioactive in stimulating angiogenesis. However, the effective ion concentration is in a narrow range from 0.79 to 1.8 μg/mL. Therefore, it is of great significance for tissue engineering applications to accurately control the ion release concentration of the calcium silicate composite scaffolds, so that the ions released from materials can remain in the effective concentration range for a long time. In this study, we prepared a variety of scaffolds with calcium silicate composite electrospun by adjusting pore size of electrospun scaffolds and controlling the location of calcium silicate nanowires inside the scaffolds, and compared ions release behavior and bioactivity in promoting proliferation of human umbilical vein endothelial cells in vitro. The results showed that, due to the hydrophobicity of polymers and limited diffusion of small pore size, electrospun scaffolds with small pore size by mixed-electrospinning or electrospinning-electrospraying calcium silicate composite displayed slow-release behavior of SiO₃ ^2- ions. In vitro cell experiments showed that the electrospun scaffolds with slow ions release promoted the proliferation of human umbilical vein endothelial cells, indicating that the bioactivity of the composite scaffolds could be regulated by adjusting ions release behavior to obtain optimal bioactivity for tissue engineering applications.