Patent ID: 8734848

Claim:
A process for the preparation of a natural or synthetic biodegradable polymeric hollow nanosphere comprising the steps of: (i) providing a template comprising polymeric polystyrene beads, mesoporous silica or diatomaceous silica; (ii) treating said template with a functionalising group to produce a functionalised template, (iii) treating said functionalised template with a solution of one or more natural or synthetic biodegradable polymers selected from the group consisting of: collagen, elastin, chitosan, hyaluronan, alginate, polyesters, PEG-based polymers, dendritic or hyperbranched polymers, and combinations thereof, and agitating to form a polymeric coating on said template; (iv) cross-linking said coating on the template with a cross-linking agent selected from the group comprising a dendrimer, a hyper-branched dendritic polymer and linear polymeric system, and combinations thereof, wherein the reactive groups in the cross-linking agent are —COOH or NH 2 , groups and the reactive groups in the polymer are —COOH or NH 2 , the molar ratio of reactive —COOH or —NH 2 groups in said dendrimer cross-linker to reactive groups —COOH or —NH 2 in said polymer is in the range 50:1 to 1:50; and (v) removing the template by treating said template with a solvent.