Drug-carrier/hydrogel scaffold for controlled growth of cells

In this work, a novel functional drug-carrier/hydrogel scaffold was prepared to control the growth of cells for tissue engineering. The drug-carrier/hydrogel scaffold was constructed from a micelle/Ca-alginate microparticles (Alg-MPs)/poly(vinyl alcohol) (PVA) hydrogel composite. In such a system, paclitaxel (PTX) is encapsulated in the micelles formed by poly(l-glutamic acid)-b-poly(propylene oxide)-b-poly(l-glutamic acid) (GPG), while human vascular endothelial growth factor-165 (VEGF₁₆₅) is loaded in the Alg-MPs. The designed function of this scaffold is to encourage the fast growth of cells such as endothelial cells (ECs) in the early period to reduce the rejection and inhibit the growth of cells such as smooth muscle cells (SMCs) in late period to prevent the vascular intimal hyperplasia. The effect of VEGF₁₆₅ is to encourage the growth of ECs, while PTX is used to inhibit the growth of smooth muscle cells (SMCs). Structure characterizations show that the drug carriers are well dispersed in the PVA hydrogel. Independent release behaviors of the two drugs are observed. VEGF₁₆₅ shows a short-term release behavior, while PTX shows a long-term release behavior from the drug-carrier/hydrogel scaffolds. Further study shows a controllable cell growth behavior on this functional drug-carrier/hydrogel scaffold via the MTT assay.