In vitro cytotoxicity of a novel injectable and biodegradable alveolar bone substitute.
ABSTRACT The unsaturated polyphosphoester (UPPE) polymer is being investigated as an injectable and biodegradable system for alveolar bone repair in the treatment of periodontal diseases. The incorporation of beta-tricalcium phosphate (beta-TCP) particles into the UPPE polymer was previously shown to significantly increase the material's mechanical properties. Moreover, in vitro experiments demonstrated that the UPPE/beta-TCP composite was capable of zero-order release of tetracycline for over 2 weeks. In this study, we investigated the in vitro cytotoxicity of each individual component, the resulting cross-linked network and the degradation products of the UPPE/beta-TCP composite using an AlamarBlue viability assay. We confirmed that each individual component except beta-TCP and the in vitro degradation products of the composite displayed a dose-dependent cytotoxic response. Once cross-linked, however, the composite did not demonstrate an adverse response. Our results suggest that the UPPE/beta-TCP composite holds great promise for use as an injectable and biodegradable alveolar bone substitute.
- [Show abstract] [Hide abstract]
ABSTRACT: While it has been shown that phosphates can target molecules and nanocarriers to bone we herein demonstrate the preparation of polyphosphate nanoparticles loaded with paclitaxel using a simple miniemulsion/solvent-evaporation technique as a model for chemotherapeutic delivery. Polyphosphates exhibit much higher structural versatility, relying on the pentavalence of the phosphorus center compared to conventional polyesters. This versatility allows for the development of new degradable polymeric carriers with inherent bone adhesion ability by the interaction of the nanoparticles with a calcium phosphate material used for bone regeneration. The novel polyphosphate nanoparticles were investigated in detail with respect to their size distribution, zeta-potential, thermal and morphological properties and were further proven to be efficiently loaded with a hydrophobic drug (up to 15 wt%). The in vitro cytotoxicity was assessed against human cancer cell lines (HeLa and Saos-2), and the paclitaxel-loaded nanoparticles showed a similar cytotoxicity profile similar to the commercially available formulation Taxomedac® and the pure paclitaxel for loading ratios of 10 wt% but additionally proved efficient adhesion on calcium phosphate granules allowing drug delivery to bone. This first report demonstrates that polyphosphate nanoparticles are promising materials for the development of systemic or local bone cancer treatment, even by direct application or by formation of composites with calcium phosphate cements.J. Mater. Chem. B. 02/2014; 2(10).
Article: Phosphorus containing hydrogels[Show abstract] [Hide abstract]
ABSTRACT: Since the discovery of poly(2-hydroxyethyl methacrylate) by Wichterle and Lim in 1960, hydrogels have been of great interest to biomedical scientists. Hydrogels are three dimensional hydrophilic polymer networks capable of swelling in water or biological fluids and retaining a large amount of fluids in the swollen state. In the last decade, hydrogels containing organophosphorus moieties were synthesized and used for proton conducting membrane, drug carriers, and scaffold for tissue engineering, pharmaceutical formulation, cosmetics, and bioseparation. One of the most versatile and rapidly developing classes of biomedical polymers is a family of polymers with a nitrogen and phosphorus backbone—polyphosphazenes. The advantage of the phosphorus–nitrogen backbone is that it can be rendered hydrolytically unstable when combined with appropriate side groups. Because of the tremendous variety of substituents that can be introduced in their structure, phosphazene polymers exhibit a very broad and sophisticated spectrum of chemical and physical properties leading to almost unlimited possibilities in the preparation of biodegradable materials Copyright © 2009 John Wiley & Sons, Ltd.Polymers for Advanced Technologies 06/2009; 20(9):707 - 722. · 1.64 Impact Factor
- [Show abstract] [Hide abstract]
ABSTRACT: A novel unsaturated polyphosphoester (UPPE) was devised in our previous research, which is a kind of promising scaffold for improving bone regeneration. However, the polymerization process of UPPE scaffolds was unfavorable, which may adversely affect the bioactivity of osteoinductive molecules added if necessary, such as recombinant human bone morphogenetic protein-2 (rhBMP2). The purpose of this study was to build a kind of optimal scaffold named UPPE-PLGA-rhBMP2 (UPB) and to investigate the bioactivity of rhBMP2 in this scaffold. Furthermore, the cytotoxicity and biocompatibility of UPB scaffold was assessed in vitro. A W1/O/W2 method was used to fabricate PLGA-rhBMP2 microspheres, and then the microspheres were added to UPPE for synthesizing UPB scaffold. The morphological characters of PLGA-rhBMP2 microspheres and UPB scaffolds were observed under the scanning electron microscopy and laser scanning confocal microscopy. The cumulative release of UPB scaffolds was detected by using ELISA. The cytotoxicity and biocompatibility of UPB scaffolds were evaluated through examining the adsorption and apoptosis of bone marrow stromal cells (bMSCs) seeded on the surface of UPB scaffolds. The bioactivity of rhBMP2 in UPB scaffolds was assessed through measuring the alkaline phosphates (ALP) activity in bMSCs seeded. The results showed that UPB scaffolds sequentially exhibited burst and sustained release of rhBMP2. The cytotoxicity was greatly reduced when the scaffolds were immersed in buffer solution for 2 h. bMSCs attached and grew on the surface of soaked UPB scaffolds, exerting well biocompatibility. The ALP activity of bMSCs seeded was significantly enhanced, indicating that the bioactivity of rhBMP2 remained and still took effect after the unfavorable polymerization process of scaffolds. It was concluded that UPB scaffolds have low cytotoxicity, good biocompatibility and preserve bioactivity of rhBMP2. UPB scaffolds are promising in improving bone regeneration.Journal of Huazhong University of Science and Technology 08/2012; 32(4):563-70. · 0.78 Impact Factor