Characterization of membranes based on cellulose acetate butyrate/poly(caprolactone)triol/doxycycline and their potential for guided bone regeneration application.

This paper discusses the feasibility of using membranes based on cellulose acetate butyrate/poly(caprolactone)triol loaded with doxycycline for guided bone regeneration. Those membranes were obtained by solvent casting varying the cellulose acetate butyrate: poly(caprolactone)triol:doxycycline (CAB:PCL-T:DOX) mass ratios and characterized by scanning electron microscopy, differential scanning calorimetry, dynamical mechanical analysis, swelling and weight loss, drug release, in vitro antimicrobial activity and in vivo inflammatory response. Neat CAB and CAB:PCL-T:DOX membranes exhibited inner porous structure, which has a pore-size reduced with increasing of the PCL-T ratio. DSC results demonstrated that the molecular dispersion of the DOX into the CAB:PCL-T membrane was conditioned by PCL-T amount. Elastic modulus reduced noticeably with increased of the PCL-T ratio in the membrane from 2 to 3, while the strain at failure showed an increase of ca. 10-fold on the same condition. The DOX release mechanism from the membranes was found to be Fickian or quasi-Fickian diffusion. Membranes assessed immediately after the preparation, and even as the membranes immersed in synthetic saliva during 7 days, demonstrated significant inhibition in the growth of Staphylococcus aureus and Escherichia coli. Subcutaneous implant test on rat in vivo showed that the CAB:PCL-T:DOX membrane (7:3:1) did not trigger chronic inflammatory responses. These results suggest the feasibility in applying the CAB:PCL-T:DOX membrane as a barrier for guided bone regeneration.

Development, characterization, and cellular adhesion of poly(L-lactic acid)/poly(caprolactone triol) membranes for potential application in bone tissue regeneration.

Poly(L-lactide)/poly(caprolactone triol) (PLLA/PCL-T) membranes were prepared by solution casting in 100/0, 90/10, and 70/30 (w/w) ratios. The membranes were analyzed by dynamic mechanical analysis, differential scanning calorimetry, and mechanical tests. The thermal analysis showed that the 90/10 and 70/30 preparations were partly miscible systems. The glass transition temperature (Tg ) of PLLA decreases as the PCL-T concentration increases, which implies that PCL-T has a plasticizer function. An in vitro study with osteoblastic cells isolated from the calvariae of rats was performed in all preparations. The results obtained in this study showed that the addition of PCL-T to the PLLA matrix modifies its mechanical, thermal, and biological properties. These blends could be useful for tissue engineering for bone applications.