Evaluation of the effect of photodynamic therapy using Rose Bengal Pigment in the Presence of Sodium Nitrite and carbon quantum dots Synthesized from Acyclovir Precursor on Growth inactivating of Herpes Simplex Virus

Purpose To evaluate whether Rose Bengal (RB) with sodium nitrite (NaNO₂) and acyclovir derived carbon quantum dots (CQDs) can photodynamically inactivate herpes simplex virus type 1 (HSV 1) in vitro. Methods Acyclovir-derived CQDs were prepared hydrothermally and characterized by high-resolution transmission electron microscopy (HRTEM) and FTIR spectroscopy. HeLa monolayers were infected with HSV-1 at a multiplicity of infection (MOI) of 0.01. Twelve experimental groups tested RB (10, 100, 1000 µg/mL) or CQDs (1, 10 mg/mL) with NaNO₂ (1 mM) in the presence or absence of green light (540 nm, 10 J cm⁻²) in different permutations. Viral titers were determined by the TCID₅₀ assay and analyzed by one-way ANOVA. Results The findings showed that PDT using the synthesized nanoparticles and Rose Bengal did not significantly reduce HSV growth in infected cell cultures. The largest numerical decreases occurred with the highest RB concentration plus light and with selected CQD combinations, but confidence intervals overlapped the control. Conclusion The limited impact of PDT on HSV growth highlights the need for further optimization of PDT protocols. The synthesis of carbon quantum dots from an antiviral precursor did not enhance antiviral activity as anticipated. This study underscores the importance of further research and clinical trials to validate PDT's therapeutic potential for HSV infections and contributes to understanding PDT mechanisms, photosensitizer combinations, and the safety of antiviral treatments for recurrent herpes labialis.