Controlling the porosity of collagen, gelatin and elastin biomaterials by ultrashort laser pulses

We report on the structural investigation of self-organized micropores generated in thin gelatin, collagen, and collagen-elastin films after single and multishot irradiation with pulse durations ranging from 30-100 fs at 800 nm. We systematically studied the effect of laser parameters: laser energy, number of pulses, and pulse duration on the development of the micropores. This work showed that applying laser pulses at different rates significantly modified the thin film surface. The results clearly revealed that femtosecond laser treatment of thin films of biomaterials: gelatin, collagen and collagen-elastin, results in creation of micro/nanopores with different size of cavity formations. Experimentally, it is demonstrated that it is possible to influence the dimensions of the pore sizes, ranging from 100 nm to 2 μm by tuning the laser parameters. We are currently further exploring the possibility of structuring these biomaterials by applying a time delay between separate pulses. First results from cell culture experiments on laser created surface foam of collagen-elastin were successfully obtained, showing the potential of the method to cultivate cells on superficial porous substrates and the preferable selectivity of the cells to proliferate on the laser modified parts of the biopolymer substrate.