Development of PLLA-based Bio Inks Applicable in the Medical Field

Sara Crivellin; Samuel Diógenes Azevedo de Souza; Mylena Stefani; Maria Ingrid Rocha Barbosa Schiavon; André Luiz Jardini; Rubens Maciel Filho; Viktor Oswavldo Cárdenas Concha

Abstract

Some synthetic polymers, such as Poly (L-lactic acid) (PLLA), are interesting to use in 3D bioprinting because they can have adaptable and resilient mechanical properties that also facilitate bioprinting processes. PLLA is a biocompatible polymer which makes it very interesting for medical applications, it is an aliphatic polyester obtained from α-hydroxy acids in different ways: ring-opening polymerization, and direct polycondensation. The use of one path over the other depends on the molecular mass to be obtained. In this work, the final polymer was obtained through the direct polycondensation route. After direct polycondensation, the PLLA produced was purified by solubilization in chloroform followed by precipitation in ethanol. Purified PLLA was produced using 0.5 g of polymer, 4 g of chloroform, and 1 g of glycerol was added to it. PLLA-based bio-ink was produced by 3D bioprinting using the extrusion technique. Before extrusion, the produced and purified material was solubilized with ethyl acetate, a non-toxic and biocompatible compound with the following proportions: PLLA 20% m*v-1 in 10 ml (95% ethyl acetate and 5% acetone v*v-1 . Finalizing, the polymer obtained was characterized by Fourier Transform Infrared Spectroscopy (FTIR), using the Bruker VERTEX 70v equipment in transmission mode with laser radiation of 633 nm wavelength, and the structure obtained with the 3D-printing was analyzed via scanning electron microscopy (SEM) to assess its surface morphology. The structure produced showed interesting properties to act as a temporary delivery device and may well hold some drugs to act as a drug delivery device.

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