New hema-based polymeric microbeads for drug delivery systems

The polymeric containers (micro or nano) reached a great influence after the development of new information referring to a new concept in the solid tumour biology: EPR effect - enhanced permeability and retention. Taking into account this concept, based on clinical and biochemical results, the solid tumours (including cancer) grow faster than the adjacent tissues, because of a better vascularization and an enhanced permeability, and, as a result, the vascularization architecture presents deficiencies. The enhanced vascular permeability is also observed in granuloma and inflammatory and infected tissues. A better retention for the nano and microparticles is observed. A very disturbing aspect, but very useful in anti-tumour treatment, is the retention tendency of the polymeric beads emphasized in the tumour against other tissues or organs. The aim of the present study was to obtain some microbeads based on functionalised HEMA polymers using the dispersive polymerisation. We expect that conjugation with some specific drugs will increase the accumulation of these microbeads within the tumours and will decrease the drug toxicity for other organs. We characterised the microbeads obtained by FTIR, SEM and FOM. We studied their in vivo distribution. We found an equal distribution into the healthy organs.