Preformed three-dimensional scaffolds with insufficient mechanical properties, poor surgical performance, and morphological mismatch to defects with irregular shape have shown drawbacks in animal evaluations and clinical applications. This motivates the development of novel injectable systems to ideally fill bone defects, allowing in situ solidification within the host tissues while retaining high initial mechanical strength and appropriate porosity. In this study, an in situ forming scaffold with time-dependent pore formation inspired by the metamorphosis of a butterfly was fabricated by incorporating gelatin microspheres (GMs) into a poly(lactic-co-glycolic acid) (PLGA)-based injectable implant. After optimizing solvent, molecular weight and solution concentration of PLGA matrix, the injectable mixture could be easily injected into both aqueous solution and random-shaped grooves while in situ solidified instantaneously. The injectability enabled an in situ morphological match within an irregular bone defect, providing high initial strength in the early period. The toughness of the injectable implant also allowed them to be easily bent into a ring without breaking. Time-dependent pore formation was accomplished by gradual degradation of GMs, generating appropriate space for tissue ingrowth in the scaffold. It is expected that the injectable in situ forming implant would aid the bone healing process by maintaining initial mechanical support and creating a spatiotemporally evolutionary microstructure during bone tissue regeneration.
The purpose of this paper was to investigate the potential of liquid crystalline (LC) gels for ophthalmic delivery, so as to enhance the bioavailability of pilocarpine nitrate (PN). The gels were prepared by a vortex method using phytantriol and water (in the ratio of 73:27 w / w ). Their inner structures were confirmed by crossed polarized light microscopy, small-angle X-ray scattering, attenuated total reflectance-Fourier transform infrared spectrum, and rheology. The in vitro release studies revealed that PN could keep sustained release from the gels over a period of 12 h. The ex vivo apparent permeability coefficient of the gels demonstrated a 3.83-folds ( P < 0.05) increase compared with that of eye drops. The corneal hydration levels of the gel maintained in the normal range of 79.46 ± 2.82%, hinting that the gel could be considered non-damaging and safe to the eyes. Furthermore, in vivo residence time evaluation suggested that a better retention performance of LC gel was observed in rabbit’s eyes compared to eye drops. In vivo ocular irritation study indicated that LC gel was nonirritant and might be suitable for various eye applications. In conclusion, LC gels might represent a potential ophthalmic delivery strategy to overcome the limitations of eye drops.
Liu Wolong,Zhang Jiupeng,Liu Qi,Pei Jianzhong,Zhu Cunzhen,Liu Peng
Micro-damages always occur and accumulate in asphalt pavement materials under the effects of temperature, vehicle loads and other factors during service. Accordingly, self-healing microcapsules could be added into asphalt binder and repair micro-damages to prevent damage extension in
time. In this study, the emulsified rejuvenator and melamine-urea-formaldehyde resin (MUF) were selected as the core and cyst wall materials, respectively, and in-situ polymerization method was applied to synthesize the novel microcapsules. The effects of emulsifier dosage and curing
time were revealed on the particle size, dispersion, surface morphology and coating properties, and the optimum process parameters were determined for microcapsules. Then, the micro morphology, molecular structure, and thermal stability were further investigated to determine the optimal preparation
of the microcapsules. Finally, the linear amplitude sweep (LAS) test was performed to evaluate the self-healing efficiency of the asphalt binder with different dosages of prepared microcapsule, and the optimal dosage of microcapsules was determined as 0.5%.
危险品化学品经营许可证（带存储）