Fabrication of pH-responsive temozolomide (TMZ)-clacked tannic acid-altered zeolite imidazole nanoframeworks (ZIF-8) enhance anticancer activity and apoptosis induction in glioma cancer cells

Glioma cancer is the primary cause of cancer-related fatalities globally for both men and women. Traditional chemotherapy treatments for this condition frequently result in reduced efficacy and significant adverse effects. This investigation developed a new drug delivery system for the chemotherapeutic drug temozolomide (TMZ) using pH-sensitive drug delivery zeolitic imidazolate frameworks (ZIF-8). These nanoplatforms demonstrate excellent biocompatibility and hold potential for cancer therapy. Utilizing the favorable reaction milieu offered by ZIFs, a 'one-pot method' was employed for the fabrication and loading of drugs, leading to a good capacity for loading. TMZ@TA@ZIF-8 NPs exhibit a notable response to an acidic milieu, resulting in an enhanced drug release pattern characterized by a controlled release outcome. The effectiveness of TMZ@TA@ZIF-8 NPs in inhibiting the migration and invasion of U251 glioma cancer cells, as well as promoting apoptosis, was confirmed through various tests, including MTT (3-(4,5)-dimethylthiahiazo(-z-y1)) assay, DAPI/PI dual staining, and cell scratch assay. The biochemical fluorescent staining assays showed that TMZ@TA@ZIF-8 NPs potentially improved ROS, reduced MMP, and triggered apoptosis in U251 cells. In U251 cells treated with NPs, the p53, Bax, Cyt-C, caspase-3, -8, and -9 expressions were significantly enhanced, while Bcl-2 expression was diminished. These outcomes show the potential of TMZ@TA@ZIF-8 NPs as a therapeutic agent with anti-glioma properties. Overall, the pH-responsive drug delivery systems we fabricated using TMZ@TA@ZIF-8 NPs show great potential for cancer treatment. This approach has the potential to make significant contributions to the improvement of cancer therapy by overcoming the problems associated with TMZ-based treatments.

Surface Modification of Magnesium Oxysulfate Whisker Based on SiO2@silane Coupling Agent and SiO2@polydopamine Double-Layer Structure for Reinforcing HDPE

In this study, we fabricated high-performance polyethylene composites by constructing SiO₂@silane coupling agent (γ-methylacryloxypropyl trimethoxysilane) and SiO₂@polydopamine (PDA) double-layer structures on a magnesium oxysulfate whisker surface. In addition to realizing strong mechanical properties, the flame-retardant properties of the composites were effectively improved. Further increase in the initial crystallization temperature of the modified composites indicated that the dispersion of whisker in the matrix was improved. The drag effect of the modified whisker on the HDPE molecular chain was characterized by dynamic mechanical thermal analysis (DMTA) and the morphology of the impact-fractured surface was characterized by scanning electron microscopy (SEM); both confirmed the improved compatibility between the whisker and the matrix. The tensile strength of HDPE/MOSw@SiO₂@KH570 and HDPE/MOSw@SiO₂@PDA composites were 22.6% and 41.5% higher than that of the HDPE/MOSw composites, respectively. The impact strengths of the HDPE/MOSw@SiO₂@KH570 and HDPE/MOSw@SiO₂@PDA composites were 129% and 102% higher than that of the HDPE/MOSw composites, respectively. A stable carbon-silicate layer constructed by a SiO₂@KH570 and SiO₂@PDA double-layer structure delayed the combustion process. As a result, the limiting oxygen index (LOI) of HDPE/MOSw@SiO₂@KH570 and HDPE/MOSw@SiO₂@PDA composites increased from 22.5 to 22.9 and 23.5, respectively.

Mussel-inspired polydopamine induced the osteoinductivity to ice-templating PLGA-gelatin matrix for bone tissue engineering application

In this study, poly(lactic-co-glycolic acid) (PLGA)-gelatin scaffolds were fabricated using the freeze-casting technique. Polydopamine (PDA) coating was applied on the surface of scaffolds to enhance the hydrophilicity, bioactivity, and cellular behavior of the composite constructs. Further, the synergistic effect of PDA coating and lamellar microstructure of scaffolds was evaluated on the promotion of properties. Based on morphological observations, freeze-casting constructs showed lamellar pore channels while the uniformity and pore size were slightly affected by deposition of PDA. The hydrophilicity and swelling capacity of the scaffolds were assessed using contact angle measurement and phosphate buffered saline absorption ratio. The results indicated a significant increment in water-matrix interactions following surface modification. The evaluation of the biodegradation ratio revealed the higher degree of degradation in PDA-coated samples owing to the presence of hydrophilic functional groups in the chemical structure of PDA. On the other hand, the bioactivity potential of PDA in the simulated body fluid solution confirmed the possibility of using coated constructs as a bone reconstructive substitute. The improvement of cellular attachment and filopodia formation in PDA-contained matrixes was the other benefit of the coating process. Furthermore, cellular proliferation and ALP activity were enhanced after PDA coating. The suggested PDA-coated PLGA-gelatin scaffolds can be applied in bone tissue regeneration.