Hybrid Poly(lactic)-Chitosan Scaffold Intensifying In Situ Bioprocessing of <em>Rindera graeca</em> Transgenic Roots for Enhanced Rinderol Production

In vitro cultured biomass of Rindera graeca , a rare endemic plant, is an efficient renewable source of bioactive naphthoquinones, e.g., rinderol, a potential bioactive inducer of apoptosis in cancer cells. Bioengineering strategies, as biomass immobilization on functionalized biomaterial-based scaffolds, elicitation by chitosan, and in situ extraction of metabolites, are tested for intensifying naphthoquinones production in R. graeca hairy roots. The aim of the study was to investigate the effects of hybrid poly(lactic)–chitosan scaffolds on biomass proliferation and rinderol production in R. graeca hairy roots. Effects of chitosan origin (fungal or squid), viscosity (10-3500 cps), and concentration (up to 45%) in the developed hybrid scaffolds have been quantitatively identified, and the results were compared to the reference culture system containing an unmodified PLA-based construct. Applying PLA–chitosan scaffold containing 33% of fungal chitosan resulted in 635 times higher rinderol production (3660 µg gDW-1) than the application of reference scaffolds. Among the tested parameters, the chitosan concentration in the hybrid scaffolds revealed significant importance in rinderol production. To sum up, the developed hybrid PLA-chitosan scaffold may be recognized as a functional key element supporting the production of naphthoquinones in cultures of R. graeca biomass.