Biodegradable manganese-doped hydroxyapatite antitumor adjuvant as a promising photo-therapeutic for cancer treatment

Application of Nanohydroxyapatite in Medicine-A Narrative Review

This review is an extensive collection of the latest literature describing the current knowledge about nanohydroxyapatite in a comprehensive way. These are hydroxyapatite particles with a size below 100 nm. Due to their size, the surface area to mass ratio of the particles increases. They are widely used in medicine due to their high potential in regenerative medicine, as a carrier of various substances, e.g., in targeted therapy. The aim of this article is to present the biological and physicochemical properties as well as the use of nanohydroxyapatite in modern medicine. Due to the potential of nanohydroxyapatite in medicine, further research is needed.

Harnessing the power of targeted metal nanocarriers mediated photodynamic and photothermal therapy

The treatment of cancer has become a profoundly intricate procedure. Traditional treatment methods, including chemotherapy, surgery and radiotherapy, have been utilized, while notable progress has been achieved in recent years. Among targeted therapies for cancer, folic acid (FA) conjugated metal-based nanoparticles (NP) have emerged as an innovative strategy, namely for photodynamic therapy (PDT) and photothermal therapy (PTT). These NP exploit the strong attraction between FA and folate receptors, which are excessively produced in several cancer cells, in order to enable precise administration and improved effectiveness of treatment. During PDT, metal-based NP functionalized with FA are used as photosensitizers which are activated by light, and produce reactive oxygen species that cause cancer cells to undergo apoptosis. Within the framework of PTT, these NP effectively transform light energy into concentrated heat, specifically targeting and destroying tumor cells. This review examines the fundamental mechanisms by which these NP improve the effectiveness of PDT and PTT while simultaneously presenting important findings that demonstrate the effectiveness of FA-functionalized MNP in laboratory and animal models. In addition, the paper also discusses the problems and potential directions for their clinical translation.

cGAS-STING pathway agonists are promising vaccine adjuvants

Adjuvants are of critical value in vaccine development as they act on enhancing immunogenicity of antigen and inducing long-lasting immunity. However, there are only a few adjuvants that have been approved for clinical use, which highlights the need for exploring and developing new adjuvants to meet the growing demand for vaccination. Recently, emerging evidence demonstrates that the cGAS-STING pathway orchestrates innate and adaptive immunity by generating type I interferon responses. Many cGAS-STING pathway agonists have been developed and tested in preclinical research for the treatment of cancer or infectious diseases with promising results. As adjuvants, cGAS-STING agonists have demonstrated their potential to activate robust defense immunity in various diseases, including COVID-19 infection. This review summarized the current developments in the field of cGAS-STING agonists with a special focus on the latest applications of cGAS-STING agonists as adjuvants in vaccination. Potential challenges were also discussed in the hope of sparking future research interests to further the development of cGAS-STING as vaccine adjuvants.

Near-Infrared Fluorescent Hydroxyapatite Nanoparticles for Targeted Photothermal Cancer Therapy

Near-infrared (NIR) fluorophores have attracted great attention due to their excellent optical and photothermal properties. Among them, a bone-targeted NIR fluorophore (named P800SO3) contains two phosphonate groups, which play important roles in binding with hydroxyapatite (HAP) as the main mineral component of bones. In this study, biocompatible and NIR fluorescent HAP nanoparticles functionalized with P800SO3 and polyethylene glycol (PEG) were readily prepared for tumor-targeted imaging and photothermal therapy (PTT). The PEGylated HAP nanoparticle (HAP800-PEG) demonstrated improved tumor targetability with high tumor-to-background ratios (TBR). Moreover, the HAP800-PEG also showed excellent photothermal properties, and the temperature of tumor tissue reached 52.3 °C under NIR laser irradiation, which could completely ablate the tumor tissue without recurrence. Therefore, this new type of HAP nanoparticle has great potential as a biocompatible and effective phototheranostic material, which enables the use of P800SO3 for targeted photothermal cancer treatment.