Preparation of poly(vinyl alcohol)/poly(lactic acid)/hydroxyapatite bioactive nanocomposites for fused deposition modeling

Abstract

Poly(vinyl alcohol)/hydroxyapatite (PVA/HA) has excellent mechanical properties and osteoconductivity that allow it to be used for cartilage repair. However, nanofillers, such as HA, cause PVA to foam during the extrusion process, making it difficult to produce filament feedstocks with uniform diameters that are suitable for fused deposition modeling (FDM). In this article, a novel method was developed to prevent the foaming of PVA‐based nanocomposites during extrusion by selectively distributing HA in the poly(lactic acid) (PLA) phase. To achieve this, HA was treated with 3‐Glycidoxypropyltrimethoxysilane (KH560). The results showed that HA treated with KH560 was segregated from the PVA phase, thus preventing the foaming of PVA. Finally, filament feedstocks with a uniform diameter of 1.75 ± 0.05 mm, which is suitable for FDM, were successfully fabricated. Meanwhile, a mathematical equation for characterizing the printability of feedstock materials was improved. The results indicated that in combination with PLA, composites with a higher compressive modulus and better melt flowability were able to be processed by FDM. Finally, complex PVA‐based bioactive nanocomposite scaffolds with high dimensional accuracy, good mechanical properties, and biocompatibility were fabricated by the FDM machine. POLYM. COMPOS., 39:E508–E518, 2018. © 2017 Society of Plastics Engineers

Engineered 3D Polymer and Hydrogel Microenvironments for Cell Culture Applications

“…Process and Material PLA is a thermoplastic widely used for 3D additive manufacturing. It is adaptable and has been used together with SLS [34,142], FDM [143][144][145][146][147][148][149], and light-assisted techniques [61,150]. For light-assisted fabrication, photopolymerizable PLA can be synthesized by methacrylation and mixed with a photo-initiator to form light active photoresin.…”

“…Concerning SLS of PLA powders, PLA was combined with calcium carbonate powder to lower bending strength to 75 MPa [34]. On the other hand in FDM of PLA, materials such as nano-hydroxyapatite (nHA) [147,148] and graphene oxide (GO) [147,149] can be mixed into the filament to enhance mechanical properties. For example Kothapalli reported the compressive modulus of PLA scaffolds to increase from 4.7 to 9.8 MPa upon the inclusion of 50 wt% nHA while the compressive strength increased from 0.29 to 0.44 MPa [154], albeit using a salt-leaching method for preparation of scaffold.…”

“…To improve bioactivity, PLA has been blended with PEG, hyaluronic acid, and chitosan [153], as well as GO to improve cell growth and attachment [147,149] and nHA for promotion of osteoconductivity [147,148]. Alternatively, nHA has been used together with PLA to decrease the adherence and proliferation of Staphylococcus aureus and Pseudomonas aeruginosa bacterial cell colonies [142].…”

Novel Synthesis of Core-Shell Biomaterials from Polymeric Filaments with a Bioceramic Coating for Biomedical Applications

“…Additive manufacturing (AM) or 3D printing can be considered 21st century technology due to the possibility to attain patient-customized and adapted products [14]. However, the most widely and accessible used technique in orthopedics is fused deposition modeling (FDM) or fused filler fabrication (FFF) [8,14,21,22], which provide 3D scaffolds with a well-defined design by extruding a digital 3D model from thermoplastic polymeric materials heated to their melting point [22].This study aims to provide a new core-shell material that can be used in the FDM technique, targeted due to its rigorous control of parameters (temperature, bed temperature, feed rate, printing speed, etc.) [23][24][25][26][27].Therefore, this study focused on the development of a completely new technique for the HA particle adhesion on PLA and TPU filaments' surface, destined for scaffolds manufacturing with applicability in both dentistry and orthopedic reconstruction surgery.When addressing the prospect of generating a ceramic coating on a polymeric surface, two important aspects are to be considered: i) the necessity (if any) of polymeric surface features modification and ii) the involved coating technique.…”

“…Additive manufacturing (AM) or 3D printing can be considered 21st century technology due to the possibility to attain patient-customized and adapted products [14]. However, the most widely and accessible used technique in orthopedics is fused deposition modeling (FDM) or fused filler fabrication (FFF) [8,14,21,22], which provide 3D scaffolds with a well-defined design by extruding a digital 3D model from thermoplastic polymeric materials heated to their melting point [22].…”