Alginate@TiO2 hybrid microcapsules with high in vivo biocompatibility and stability for cell therapy

Encapsulation of stem-cell derived β-cells: A promising approach for the treatment for type 1 diabetes mellitus

Type 1 diabetes mellitus is an auto-immune disease causing the T-cell mediated destruction of insulin-producing β-cells, resulting in chronic hyperglycemia. Current treatments such as insulin replacement therapy or the transplantation of pancreas or pancreatic islets present major disadvantages such as the constant need of drugs, as well as a shortage of donor organs. In this review, we discuss a sustainable solution to overcome these limitations combining the use of β-cells, derived from stem cells, and their encapsulation within a protective matrix. This article provides an exhaustive overview of currently investigated stem cell sources including embryonic, mesenchymal as well as induced pluripotent stem cells in combination with various up to date encapsulation methods allowing the formation of immuno-protective devices. In order to identify current limitations of this interdisciplinary therapeutic approach and to find sustainable solutions, it is essential to consider key aspects from all involved domains. This includes biological parameters such as the stem cell origin but also the different aspects of the encapsulation process, the used materials and their physico-chemical properties such as elasticity, porosity and permeability cut-off as well as the best implantation sites allowing efficient and self-autonomous control of glycemia by the transplanted encapsulated cells.

Decanoic acid-palmitic acid/SiO2@TiO2 phase change microcapsules based on RBF model with excellent photocatalysis performance and humidity control property

The decanoic acid-palmitic acid composite phase change material compounds with SiO₂ and TiO₂ to prepare decanoic acid-palmitic acid/SiO₂@TiO₂ phase change microcapsules (D-P-SiO₂@TiO₂ PCM). The D-P-SiO₂@TiO₂ PCM could show efficient temperature regulation, remove pollutants through photocatalysis, and control air humidity. However, it is difficult to obtain the best experimental scheme directly using the traditional experimental setup due to the complicated photocatalytic-humidity performance. The radial basis function (RBF) model optimized the uniform experimental design parameters, and the D-P-SiO₂@TiO₂ PCM showed enhanced photocatalytic-humidity performance. The RBF-calculated preparation parameters were as follows: the molar ratio of decanoic acid-palmitic acid to tetraethyl silicate was 0.42, pH was 1.83, the molar ratio of deionized water to tetraethyl silicate was 98.15, while the molar rate of tetrabutyl titanate to tetraethyl silicate was 0.76. The degradation rate of gaseous formaldehyde by the RBF-optimized D-P-SiO₂@TiO₂ PCM was 69.57% after 6 h, and the moisture content was between 0.0923 and 0.0940 g·g^-1 at 43.16-75.29% relative humidity (RH). The comparison between model optimization and the experiment sample prepared using the optimized parameters showed that the theoretical photocatalytic-humidity performance target value was 2.0502, and the tested target value was 2.0757. The error calculated from these two values was only 1.24%, and both were better than the best value of uniform experimental calculation. RBF mathematical model was proved to be an effective, convenient, and economic-saving method to simulate and predict D-P-SiO₂@TiO₂ PCM experimental design parameters. SEM and TEM analyses of the RBF-optimized D-P-SiO₂@TiO₂ PCM showed a uniform spherical structure, and the particle size analysis analyses was about 200 nm. The DSC analysis showed the phase transition temperature range was between 16.97 and 28.94 °C, within the comfort range of the human body. The UV-Vis investigations showed the absorption edge of the RBF-optimized D-P-SiO₂@TiO₂ PCM was 380 nm, in line with the band gap structure of the TiO₂ anatase phase. The thermogravimetric investigations showed that this composite was stable at normal temperature and pressure. After a 100 times hot-cold cycle, the quality of the RBF-optimized D-P-SiO₂@TiO₂ PCM maintained its stability, as the photocatalytic-humidity performance was almost the same. The N₂-adsorption analysis showed it had a high specific surface area and irregular pore structures, which could help it regulate air humidity. Considering these results, the D-P-SiO₂@TiO₂ PCM, a new ecological functional material, would be used in the construction industry to improve the architectural ecological environment.

In Vivo and In Vitro Biocompatibility Study of CuS Nanoparticles: Photosensitizer for Glioblastoma Photothermal Therapy

Although photothermal treatment (PTT) has made significant progress in the fight against cancer, certain types of malignant tumors are still difficult to eradicate. PTT uses photothermal transforming agents to absorb NIR light and convert it to thermal energy, causing cancer cell death. In this study, we synthesized alginate (Alg)-coated CuS nanoparticles (CuS@Alg) as photothermal transforming agents to kill glioblastoma cancer cells. Nanoparticles were synthesized via a facile method, then, were characterized with different techniques such as ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FTIR), X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Nanoparticles show high stability, and are monodisperse. CuS@Alg was discovered to have a spherical shape, a hydrodynamic size of about 19.93 nm, and a zeta potential of - 9.74 mV. CuS@Alg is able to increase temperature of medium under NIR light. Importantly, in vitro investigations show that PTT based on CuS@Alg has a strong theraputic impact, resulting in much high effectiveness. The LD50 and histopathology assays were used to confirm the NPs' non-toxicity in vivo. Results from an in vivo subacute toxicity investigation showed that the fabricated NPs were perfectly safe to biomedical usage.

Preparation of Hybrid Sol-Gel Materials Based on Living Cells of Microorganisms and Their Application in Nanotechnology

Microorganism-cell-based biohybrid materials have attracted considerable attention over the last several decades. They are applied in a broad spectrum of areas, such as nanotechnologies, environmental biotechnology, biomedicine, synthetic chemistry, and bioelectronics. Sol-gel technology allows us to obtain a wide range of high-purity materials from nanopowders to thin-film coatings with high efficiency and low cost, which makes it one of the preferred techniques for creating organic-inorganic matrices for biocomponent immobilization. This review focuses on the synthesis and application of hybrid sol-gel materials obtained by encapsulation of microorganism cells in an inorganic matrix based on silicon, aluminum, and transition metals. The type of immobilized cells, precursors used, types of nanomaterials obtained, and their practical applications were analyzed in detail. In addition, techniques for increasing the microorganism effective time of functioning and the possibility of using sol-gel hybrid materials in catalysis are discussed.