Conventional photothermal therapy (PTT) irradiates the tumor tissues by elevating the temperature above 48 °C to exert thermal ablation, killing tumor cells. However, thermal ablation during PTT harmfully damages the surrounding normal tissues, post-treatment inflammatory responses, rapid metastasis due to the short-term mass release of tumor-cellular contents, or other side effects. To circumvent this limitation, mild-temperature photothermal therapy (MTPTT) was introduced to replace PTT as it exerts its activity at a therapeutic temperature of 42–45 °C. However, the significantly low therapeutic effect comes due to the thermoresistance of cancer cells as MTPTT figures out some of the side-effects issues. Herein, our current review suggested the mechanism and various strategies for improving the efficacy of MTPTT. Especially, heat shock proteins (HSPs) are molecular chaperones overexpressed in tumor cells and implicated in several cellular heat shock responses. Therefore, we introduced some methods to inhibit activity, reduce expression levels, and hinder the function of HSPs during MTPTT treatment. Moreover, other strategies also were emphasized, including nucleus damage, energy inhibition, and autophagy mediation. In addition, some therapies, like radiotherapy, chemotherapy, photodynamic therapy, and immunotherapy, exhibited a significant synergistic effect to assist MTPTT. Our current review provides a basis for further studies and a new approach for the clinical application of MTPTT.
Poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) are versatile drug nanocarriers with a wide spectrum of applications owing to their extensive advantages, including biodegradability, non-toxic side effects, and low immunogenicity. Among the numerous nanoparticle preparation methods available for PLGA NPs (the hydrophobic polymer), one of the most extensively utilized preparations is the sonicated-emulsified solvent evaporation method, owing to its simplicity, speed, convenience, and cost-effectiveness. Nevertheless, several factors can influence the outcomes, such as the types of concentration of the surfactants and organic solvents, as well as the volume of the aqueous phase. The objective of this article is to explore the influence of these factors on the properties of PLGA NPs and their drug release behavior following encapsulation. Herein, PLGA NPs were fabricated using bovine serum albumin (BSA) as a surfactant to investigate the impact of influencing factors, including different water-soluble organic solvents such as propylene carbonate (PC), ethyl acetate (PA), and dichloromethane (DCM). Notably, the size of PLGA NPs was smaller in the EA group compared to that in the DCM group. Moreover, PLGA NPs showed excellent stability, ascribed to the presence of the BSA surfactant. Furthermore, PLGA NPs were co-loaded with varying concentrations of hydrophilic drugs (doxorubicin hydrochloride) and hydrophobic drugs (celecoxib), and exhibited pH-sensitive drug release behavior in PBS with pH 7.4 and pH 5.5.
During fixed orthodontic treatment, white spot lesions are prevalent issues associated with cariogenic bacteria. This study aims to construct an orthodontic adhesive containing nanoparticles of amorphous calcium phosphate-polydopamine-Ag (NPA) fillers to combat white spot lesions. The NPA fillers were prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The biocompatibility of the fillers was evaluated. A colony counting test evaluated the antibacterial property of the fillers against Streptococcus mutans (S. mutans). NPA fillers were mixed with orthodontic adhesive (Transbond XT) at different weight ratios (0, 0.1, 0.2, 0.3, and 0.5 wt.%). The shear bond strength and antibacterial properties were then further investigated. The results showed that NPA was prepared successfully, with good antibacterial properties. The cell survival rate of all groups of fillers was higher than 70%, showing good biocompatibility. Moreover, the shear bond strength of the orthodontic adhesive with 0.2 wt.% NPA fillers was 11.89 ± 1.27 MPa, meeting the minimal clinical bond strength requirements of 7.8 MPa. Furthermore, the orthodontic adhesive resin blocks and the extract displayed good antibacterial properties, with the number of colonies decreasing significantly (p < 0.001). Taken together, we think that an orthodontic adhesive with NPA may have a good application potential for the prevention and treatment of white spot lesions.