Biodegradable and biocompatible hyperbranched polymers are synthesized and their potential for dermal drug delivery is investigated.

Despite immense investigations in the field of cancer diagnosis and therapy in recent decades, cancer is still the major cause of morbidity and mortality all over the world. Recently, with the advancement of nanotechnology, designing and preparation of efficient nano-sized structures having the potential of diagnosis and treatment of cancer have been proposed. Among different types of nano-sized materials, biocompatible polymers are seemed to be innovative tools with huge potential in cancer treatment. Advancement in polymer chemistry 10 55 gene delivery 2-7 , cancer diagnosis and therapy 8-11 , nanocarriers 12, 13 , nanomedicine 14-16 , and biomedical applications.

In this work we report on a new method for the cationic polymerization of glycidol by citric acid at ambient and solvent free conditions. In this polymerization, citric acid is a proton donor and is able to incorporate in the structure of polyglycerol by reaction with the activated monomer. The molecular weight and degree of branching of the synthesized polymers are affected by the glycidol/citric acid molar ratios and reaction temperature. Due to the citric acid core of the hyperbranched polyglycerols, they are able to break down into the smaller segments at neutral or acidic conditions. Apart from citric acid, glycidol, and water, other reagents or organic solvents have not been used in the synthetic and purification processes. Taking advantage of the green synthesis and ability to cleave under physiological conditions, in addition to the intrinsic biocompatibility of polyglycerol, the synthesized polymers are promising candidates for future biomedical applications.

Inflammatory processes are beneficial responses to overcome injury or illness. Knowledge of the underlying mechanisms allows for a specific treatment. Thus, synthetic systems can be generated for a targeted interaction. In this context, dendritic polyglycerol sulfates (dPGS) have been investigated as anti-inflammatory compounds. Biodegradable systems are required to prevent compound accumulation in the body. Here we present biodegradable analogs of dPGS based on hyperbranched poly(glycidol-co-caprolactone) bearing a hydrophilic sulfate outer shell (hPG-co-PCLS). The copolymers were investigated regarding their physical and chemical properties. The cytocompatibility was confirmed using A549, Caco-2, and HaCaT cells. Internalization of hPG-co-PCLS by A549 and Caco-2 cells was observed as well. Moreover, we demonstrated that hPG-co-PCLS acted as a competitive inhibitor of the leukocytic cell adhesion receptor L-selectin. Further, a reduction of complement activity was observed. These new biodegradable dPGS analogs are therefore attractive for therapeutic applications regarding inflammatory diseases.