Revisiting the evidence of photodynamic therapy for oral potentially malignant disorders and oral squamous cell carcinoma: an overview of systematic reviews

BACKGROUND

This study summarized the available evidence about the use of photodynamic therapy (PDT) for the management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC).

METHODS

An overview of systematic reviews was undertaken based on the 2020 PRISMA statement. Electronic searches were performed in five databases. Studies published up to November 2022 were included. Risk of bias was assessed with the AMSTAR 2 tool.

RESULTS

A total of 30 studies enrolling 9,245 individuals with OPMD (n=7,487) or OSCC (n=1,758) met the selection criteria. All studies examined the efficacy and/or safety of PDT. OPMD were investigated individually in 82.8% of the studies, the most common being oral lichen planus and actinic cheilitis. OSCC was addressed separately in 10.3% of the studies, while only 6.9% evaluated both OPMD and OSCC. Fourteen different types of photosensitizers were described. PDT was used according to the following setting parameters: 417-670 nm, 10-500 mW/cm², 1.5-200 J/cm², and 0.5-143 minutes. Regarding OPMD, leukoerythroplakia showed the best response rates, while oral lichen planus presented a partial or no response in nearly 75% of documented cases. A complete response was observed in 85.9% of OSCC cases, while 14.1% had no resolution.

CONCLUSION

Overall, the response to PDT depended on the type of OPMD/OSCC and the parameters used. Although PDT is an emerging candidate for the treatment of OPMD and OSCC, there is heterogeneity of the methodologies used and the clinical data obtained, particularly regarding the follow-up period.

Development of A Thermo-Responsive Conjugated Polymer with Photobleaching-Resistance Property and Tunable Photosensitizing Performance

A thermo-responsive conjugated polymer, PFBT-gPA is synthesized by grafting the poly(N-isopropylacrylamide) (PNIPAAm) to the side chains of a conjugated polyfluorene derivative through atom transfer radical polymerization (ATRP). PFBT-gPA undergoes a reversible phase transition in water below and above the lower critical solution temperature (LCST) and the process is studied by differential scanning calorimetry (DSC) analysis and UV/vis absorption spectra. PFBT-gPA shows a good photostability under UV light irradiation especially above the LCST. Moreover, the photosensitizing performance of PFBT-gPA could be tuned simply by changing temperature. The unique properties of PFBT-gPA promise its potential applications in sensing and photodynamic therapy.

Lactose esters: synthesis and biotechnological applications

Biodegradable nonionic sugar esters-based surfactants have been gaining more and more attention in recent years due to their chemical plasticity that enables the various applications of these molecules. In this review, various synthesis methods and biotechnological implications of lactose esters (LEs) uses are considered. Several chemical and enzymatic approaches are described for the synthesis of LEs, together with their applications, i.e. function in detergents formulation and as additives that not only stabilize food products but also protect food from undesired microbial contamination. Further, this article discusses medical applications of LEs in cancer treatment, especially their uses as biosensors, halogenated anticancer drugs, and photosensitizing agents for photodynamic therapy of cancer and photodynamic inactivation of microorganisms.