Propolis is a honeybee product that contains a mixture of natural substances with a broad spectrum of biological activities. However, the clinical application of propolis is limited due to the presence of a myriad of constituents with different physicochemical properties, low bioavailability and lack of appropriate formulations. In this study, a modified injection technique (spraying technique) has been developed for the encapsulation of the Egyptian propolis within liposomal formulation. The effects of three variables (lipid molar concentration, drug loading and cholesterol percentage) on the particle size and poly dispersity index (PDI) were studied using response surface methodology and the Box–Behnken design. Response surface diagrams were used to develop an optimized liposomal formulation of the Egyptian propolis. A comparative study between the optimized liposomal formulation prepared either by the typical ethanol injection method (TEIM) or the spraying method in terms of particle size, PDI and the in-vitro anti-proliferative effect against human melanoma cell line A375 was carried out. The spraying method resulted in the formation of smaller propolis-loaded liposomes compared to TEIM (particle sizes of 90 ± 6.2 nm, and 170 ± 14.7 nm, respectively). Furthermore, the IC50 values against A375 cells were found to be 3.04 ± 0.14, 4.5 ± 0.09, and 18.06 ± 0.75 for spray-prepared propolis liposomes (PP-Lip), TEIM PP-Lip, and propolis extract (PE), respectively. The encapsulation of PE into liposomes is expected to improve its cellular uptake by endocytosis. Moreover, smaller and more uniform liposomes obtained by spraying can be expected to achieve higher cellular uptake, as the ratio of liposomes or liposomal aggregates that fall above the capacity of cell membrane to “wrap” them will be minimized.

After the COVID-19 pandemic, mRNA-based vaccines have emerged as a revolutionary technology in immunization and vaccination. These vaccines have shown remarkable efficacy against the virus and opened up avenues for their possible application in other diseases. This has renewed interest and investment in mRNA vaccine research and development, attracting the scientific community to explore all its other applications beyond infectious diseases. Recently, researchers have focused on the possibility of adapting this vaccination approach to cancer immunotherapy. While there is a huge potential, challenges still remain in the design and optimization of the synthetic mRNA molecules and the lipid nanoparticle delivery system required to ensure the adequate elicitation of the immune response and the successful eradication of tumors. This review points out the basic mechanisms of mRNA-LNP vaccines in cancer immunotherapy and recent approaches in mRNA vaccine design. This review displays the current mRNA modifications and lipid nanoparticle components and how these factors affect vaccine efficacy. Furthermore, this review discusses the future directions and clinical applications of mRNA-LNP vaccines in cancer treatment.