Thiolated-Polymer-Based Nanoparticles as an Avant-Garde Approach for Anticancer Therapies—Reviewing Thiomers from Chitosan and Hyaluronic Acid

Abstract

Thiomers (or thiolated polymers) have broken through as avant-garde approaches in anticancer therapy. Their distinguished reactivity and properties, closely linked to their final applications, justify the extensive research conducted on their preparation and use as smart drug-delivery systems (DDSs). Multiple studies have demonstrated that thiomer-rich nanoformulations can overcome major drawbacks found when administering diverse active pharmaceutical ingredients (APIs), especially in cancer therapy. This work focuses on providing a complete and concise review of the synthetic tools available to thiolate cationic and anionic polymers, in particular chitosan (CTS) and hyaluronic acid (HA), respectively, drawing attention to the most successful procedures. Their chemical reactivity and most relevant properties regarding their use in anticancer formulations are also discussed. In addition, a variety of NP formation procedures are outlined, as well as their use in cancer therapy, particularly for taxanes and siRNA. It is expected that the current work could clarify the main synthetic strategies available, with their scope and drawbacks, as well as provide some insight into thiomer chemistry. Therefore, this review can inspire new research strategies in the development of efficient formulations for the treatment of cancer.

Anti-Cancer and Electrochemical Properties of Thiogenistein—New Biologically Active Compound

“…Additionally, the presence of the -SH group in the new substituent may be responsible for the correct thiol-disulfide balance and the associated oxidation-reduction potential of cells. A similar mechanism is observed for glutathione which is a natural antioxidant [49].…”

Recent Advances in Chitosan and its Derivatives in Cancer Treatment

“…The abundant amino and hydroxyl groups on the chitosan skeleton represent more target parts of chemical modification, which improves water solubility and endow chitosan with some new functions, such as targeted and environmentally sensitive drug release, and enhances therapeutic effect and minimize side effects. The most common chitosan derivatives used as drug carriers include thiochitosan, trimethyl chitosan, carboxymethyl chitosan, ethylene glycol chitosan and so on ( Hu et al, 2020 ; Grosso and De-Paz, 2021 ; Li et al, 2021 ).…”

“…Among the various available therapies, chemotherapy is still one of the most important treatment measures for most cancer patients, which is regarded as one of the main treatment approaches to prevent cancer cell proliferation. However, the active chemicals used to treat cancer usually do not distinguish cancer cells from healthy cells because both are exposed to cytotoxic chemotherapeutic drugs, which results in a high rate of severe adverse reactions and limits its therapeutic effect ( Grosso and De-Paz, 2021 ). To improve therapeutic potency and minimize the side effects, more targeted therapies are highly needed ( Perez-Herrero and Fernandez-Medarde, 2015 ).…”

Scope and Limitations of Current Antibiotic Therapies against Helicobacter pylori: Reviewing Amoxicillin Gastroretentive Formulations

“…Secondly, the flexibility of the polymer chains promotes the final mucoadhesive performance and, thirdly, the existence of ionic groups or/and proton donor or acceptor groups (such as hydroxyl, carboxyl, sulfate, and amino groups) is beneficial as they can participate in the formation of electrostatic or/and hydrogen bonds. Interestingly, polymers functionalized with sulfhydryl groups can render reversible disulfide linkages with mucin [ 95 ].…”