Thermal and dynamic mechanical characterization of acrylic bone cements modified with biodegradable polymers

Abstract

In this work, a thermal and a dynamic mechanical study of new formulations self-curing acrylic bone cements is reported. The basic formulation of poly(methylmethacrylate) (PMMA)-based acrylic bone cements has been modified with biodegradable polyesters such as poly(L-lactic acid), poly(b-hydroxybutyrate), and different kinds of thermoplastic starches. Differential scanning calorimetry (DSC) (dynamic and isothermal conditions), thermogravimetric analysis (TGA), dynamic mechanical thermal analysis (DMTA), and scanning electron microscopy (SEM) were used to determine the influence of the biodegradable polymer in the behavior of the biomedical formulations. DSC assay revealed a strong dependence of the polymerization enthalpy (DH cur ) with increasing solid : liquid ratio and a low influence of the nature of the added biodegradable polymer on glass transition. TGA analysis showed the different mechanism of PMMA-biodegradable polymer interaction depending on the solubilization of the added polymer in methylmethacrylate monomer during curing. DMTA showed the reinforcing capacity of segregated phases of the polymer included in the cement. The solubilization of aliphatic polyesters in the resulting PMMA polymerized phase led to a drop in mechanical stiffness observed from storage modulus (E 0 ) profiles. Moreover, tan d shifts to higher temperatures (4-7 C) during a second scan, confirming the presence of residual monomer content.

Novel Bioactive and Antibacterial Acrylic Bone Cement Nanocomposites Modified with Graphene Oxide and Chitosan

“…The glass transition temperature (T g ) calculated from the tan δ (Table 1 and Figure 7), shows similar behavior to the compressive strength, finding a reduction in this parameter with the incorporation of CS mainly due to the lower degree of mechanical reinforcement that is related to the hardness of the material. Marques et al [42] reported glass transition values of materials modified with biodegradable polymers similar to those found in this investigation.…”

Characterization and use of ultraviolet‐reactive low‐molecular‐weight polyhydroxybutyrate to prepare biodegradable acrylates

“…Consequently, although the weight loss rates or the biodegradation rates of ACRY/LMWPHB increased with the LMWPHB content, they were also much smaller than those of pHEMA/LMWPHB and changed less drastically during the testing period, especially in the first 15 days. The results indicate that the biodegradation properties of various acrylate/LMWPHB copolymers could be modified and controlled by changes in the hydrophilic properties of the acrylic constituents and could generate many diversified applications, such as artificial skin manufacturing/dressings, marrow/spinal cord cell regeneration, drug delivery, scaffolds for cell adhesion and artificial cartilage production, and bone cements, as mentioned previously . The studied materials with the combined mechanical and biodegradation properties not only could result in bioactive and biodegradable second‐generation biomaterials but could also further result in third‐generation materials capable of stimulating specific cellular responses at the molecular level for new biomedical applications …”

“…The results indicate that the biodegradation properties of various acrylate/LMWPHB copolymers could be modified and controlled by changes in the hydrophilic properties of the acrylic constituents and could generate many diversified applications, such as artificial skin manufacturing/dressings, marrow/spinal cord cell regeneration, drug delivery, scaffolds for cell adhesion and artificial cartilage production, and bone cements, as mentioned previously. 28,[40][41][42][43][44][45][46][47][48] The studied materials with the combined mechanical and biodegradation properties not only could result in bioactive and biodegradable second-generation biomaterials but could also further result in third-generation materials capable of stimulating specific cellular responses at the molecular level for new biomedical applications. 50,51 The surface morphology of the ACRY/LMWPHB specimens after the biodegradation test is also shown in Figures 10 and 11.…”

“…In this study, the detailed chemical characterization of the prepared LMWPHB via the thermal treatment of PHB in a solvent and the use of LMWPHB to prepare different photopolymerized polyacrylates (hydrophobic and hydrophilic) were demonstrated. Polyacrylates are common materials that are popularly used in coatings, inks, commodity products, optical lenses [e. g., hydrophilic poly(hydroxyethyl methacrylate) (pHEMA) hydrogels for disposable contact lenses and treated hydrophobic pHEMA for traditional long‐wearing contact lenses], biomedical products [e.g., pHEMA used for artificial skin manufacturing/dressings, marrow/spinal cord cell regeneration, drug delivery, scaffolds for cell adhesion and artificial cartilage production and poly(methyl methacrylate) (PMMA) for bone cements], and so on . In general, polyacrylates may have biocompatibility, but they are not biodegradable.…”

“…Polyacrylates are common materials that are popularly used in coatings, inks, commodity products, optical lenses [e. g., hydrophilic poly(hydroxyethyl methacrylate) (pHEMA) hydrogels for disposable contact lenses and treated hydrophobic pHEMA for traditional long-wearing contact lenses], biomedical products [e.g., pHEMA used for artificial skin manufacturing/dressings, marrow/spinal cord cell regeneration, drug delivery, scaffolds for cell adhesion and artificial cartilage production and poly(methyl methacrylate) (PMMA) for bone cements], and so on. 28,[40][41][42][43][44][45] In general, polyacrylates may have biocompatibility, but they are not biodegradable. It is shown here that the mechanical and biodegradation properties of the prepared polyacrylates changed with the amount of LMWPHB added and the hydrophilic properties of the monomers used.…”