Multilayered drug delivery coatings composed of daidzein-loaded PHBV microspheres embedded in a biodegradable polymer matrix by electrophoretic deposition

Abstract

The development of drug delivery coating systems for local and long-term drug release is gaining increasing interest especially to functionalize bioinert implants with osseointegration and antibacterial properties. In this study, a biodegradable drug delivery coating platform consisting of drug-loaded PHBV microspheres embedded in an alginate-PVA matrix was fabricated by a one-step electrophoretic deposition (EPD) process. Layer by layer (LbL) deposition was exploited to generate chitosan-alginate multilayers on the EPD-produced coating to enlarge the diffusional barrier around the microspheres for controlled drug release. Daidzein, selected as a model drug due to its anti-osteoporosis properties, was pre-encapsulated in PHBV microspheres. The parameters for microsphere fabrication were optimized by an orthogonal design approach. The loading efficiency of daidzein in both the microspheres and in the deposited coatings was adjusted by varying the processing parameters during microsphere fabrication and the EPD process. The degradation of the deposited multilayers was investigated in PBS for up to 14 days. The degradation rate, surface roughness and wettability, as well as adhesion strength of the coatings during degradation were evaluated by applying a range of techniques. A controlled and sustained daidzein release was detected from both free microspheres and microsphere-containing coatings. Finally cytotoxicity and stimulatory effects of daidzein or daidzein-loaded coatings, on both MC3T3-E1 and RAW264.7 cell lines, were studied to validate the potential of the developed coatings for orthopedic applications.

Bilayered BMP2 Eluting Coatings on Graphene Foam by Electrophoretic Deposition: Electroresponsive BMP2 Release and Enhancement of Osteogenic Differentiation

“…According to the long-term BMP2 release test, we could conclude that BMP2 was successfully immobilized on GF during EPD and released in a controlled manner for up to 10 days. The long-term release curve represented a typical diffusion-based release characteristic which is in agreement with the Peppas equation and our previous investigation, indicating a diffusion-based release mechanism. Additionally, our electroresponsive release experiment presented significantly different BMP2 release behaviors influenced by the electric field.…”

“…EPD is a simple, rapid, and room-temperature coating technique that involves the movement of charged particles/molecules under an appropriate electric field, leading to their consolidation on the oppositely charged electrode to form films and coatings with high microstructural homogeneity and tailored thickness . With the proper design of EPD suspension, e.g., the addition of polyelectrolytes (chitosan “+” or alginate “–”) which act as the charger in suspension and as the binder in the deposit, functional molecules dispersed in EPD suspension are able to migrate and robustly bonded to the oppositely electrode under an electric field. − Furthermore, the presence of amino or carboxylic groups on polyelectrolyte chains facilitated the pH-responsive property of the deposited coatings, which could be used to design stimuli-responsive drug delivery systems. Combining the conductive charter of GF and the pH sensitivity of EPD coatings, it is expected that the electric field exerted on GF may play a role in controlling the BMP2 release from the deposited coatings.…”

Poly (3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) improved osteogenic differentiation of the human induced pluripotent stem cells while considered as an artificial extracellular matrix

“…In another study, Huang et al reported that PHBV applications in the microsphere form to improve the bone conduction and mechanical strength of PLGA scaffolds, and their results showed that this ability increased from about 30% to 80% (Huang, Shi, Ren, Du, & Wang, ). We tried to introduce a cell‐co‐polymer construct that has a great ability for use in bone tissue engineering applications, however, several studies were also tried to improve PHBV osteoconductivity or mechanical properties by blending with other polymers or nano‐composites such as calcium phosphate and gelatin (Duan & Wang, ), PLLA and collagen (Sultana, ), bioactive glass (J. Wu, Wu, Xue, Li, & Liu, ), nano strontium carbonate and Platelet Rich Plasma layer (Sajesh, Kiran, Nair, & Jayakumar, ) and daidzein and PVA (Chen et al, ) for bone tissue engineering application. However, our results demonstrated PHBV alone can be used in bone tissue engineering with appropriate stem cells cultured on it, and this strategy is better than manipulation of the PHBV, whereas its properties could be modified and its degradation products can be turned into harmful.…”

Advancing bone tissue engineering one layer at a time: a layer-by-layer assembly approach to 3D bone scaffold materials

“…29 Numerous studies have reported the use of LbL assembly to incorporate proteins, growth factors, polysaccharides, nucleic acids, and functional peptides into biomaterials, and to deposit coatings with controlled degradation rates. [30][31][32][33][34] In addition, the physicochemical properties of multilayer films such as topography, stiffness and strength, and hydrophobicity can be optimized by altering the coating composition and processing parameters, which in turn enables control over biological cellular responses. 35,36 The bone tissue engineering field faces numerous challenges including difficulties of in vitro cell culture, mimicking osteogenesis in native tissue, the cost and complexity of manufacturing, and achieving biomaterial scaffolds that satisfy the diverse structural, mechanical and biological properties required for bone tissue engineering applications.…”