3D Bioplotter Research Papers

Displaying all papers about PLLA (11 results)

Printability and critical insight into polymer properties during direct- extrusion based 3D printing of medical grade polylactide and copolyesters

Biomacromolecules 2019

Various 3D printing techniques currently use degradable polymers such as aliphatic polyesters to create well-defined scaffolds. Even though degradable polymers are influenced by the printing process, and this subsequently affects the mechanical properties and degradation profile, degradation of the polymer during the process is not often considered. Degradable scaffolds are today printed and cell-material interactions evaluated without considering the fact that the polymer change while printing the scaffold. Our methodology herein was to vary the printing parameters such as temperature, pressure, and speed to define the relationship between printability, polymer microstructure, composition, degradation profile during the process and rheological behavior….

PLLA PCLA PLGA

Achieving Molecular Orientation in Thermally Extruded 3D Printed Objects

Biofabrication 2019

3D printing is used to fabricate tissue scaffolds. The polymer chains in these objects are typically unoriented. The mechanical properties of these scaffolds can be significantly enhanced by proper alignment of the polymer chains. But, post-processing routes to increase orientation can be limited by the geometry of the printed object. Here we show that it is possible to orient the polymer chains during printing by optimizing the printing parameters to take advantage of the flow characteristics of the polymer. This is demonstrated by printing a polymeric scaffold for meniscus regeneration using poly(desaminotyrosyl-tyrosine dodecyl dodecanedioate), poly(DTD DD). Alignment of the polymer…

Determination Of The Geometrical And Viscoelastic Properties Of Scaffolds Made By Additive Manufacturing Using Bioplotter

Lekar a technika – Clinician and Technology 2017 Volume 47, Issue 3, pages 88–95

Additive Manufacturing (AM) is a name of a group of technologies that build 3D objects by adding layer-upon-layer of material. There are many technologies, including Rapid Prototyping (RP), Direct Digital Manufacturing (DDM), layered manufacturing and additive fabrication. Many types of materials can be used for AM technology. Biodegradable polymers such as polylactic acid (PLA) and polyhydroxybutyrate (PHB), are currently the subject of intensive research in the field of additive manufacturing and regenerative medicine. A number of biodegradable and bioresorbable materials, as well as scaffold designs, have been experimentally and clinically studied in many research facilities around the world. For effective…

Fabrication of Highly Stretchable Conductors Based on 3D Printed Porous Poly(dimethylsiloxane) and Conductive Carbon Nanotubes/Graphene Network

ACS Applied Materials & Interfaces 2016 Volume 8, Issue 3, Pages 2187–2192

The combination of carbon nanomaterial with three-dimensional (3D) porous polymer substrates has been demonstrated to be an effective approach to manufacture high-performance stretchable conductive materials (SCMs). However, it remains a challenge to fabricate 3D-structured SCMs with outstanding electrical conductivity capability under large strain in a facile way. In this work, the 3D printing technique was employed to prepare 3D porous poly(dimethylsiloxane) (O-PDMS) which was then integrated with carbon nanotubes and graphene conductive network and resulted in highly stretchable conductors (OPCG). Two types of OPCG were prepared, and it has been demonstrated that the OPCG with split-level structure exhibited both higher…

Diffraction tomography and Rietveld refinement of a hydroxyapatite bone phantom

Journal of Applied Crystallography 2016 Volume 49, Pages 103-109

A model sample consisting of two different hydroxyapatite (hAp) powders was used as a bone phantom to investigate the extent to which X-ray diffraction tomography could map differences in hAp lattice constants and crystallite size. The diffraction data were collected at beamline 1-ID, the Advanced Photon Source, using monochromatic 65 keV X-radiation, a 25 × 25 µm pinhole beam and translation/rotation data collection. The diffraction pattern was reconstructed for each volume element (voxel) in the sample, and Rietveld refinement was used to determine the hAp lattice constants. The crystallite size for each voxel was also determined from the 00.2 hAp…

Hydroxyapatite PLLA

3D-Bioprinting of Polylactic Acid (PLA) Nanofibers-Alginate Hydrogel Bioink Containing Human Adipose-Derived Stem Cells

ACS Biomaterials Science and Engineering 2016 Volume 2, Issue 10, Pages 1732–1742

Bioinks play a central role in 3D-bioprinting by providing the supporting environment within which encapsulated cells can endure the stresses encountered during the digitally-driven fabrication process, and continue to mature, proliferate, and eventually form extracellular matrix (ECM). In order to be most effective, it is important that bioprinted constructs recapitulate the native tissue milieu as closely as possible. As such, musculoskeletal soft tissue constructs can benefit from bioinks that mimic their nanofibrous matrix constitution, which is also critical to their function. This study focuses on the development and proof-of-concept assessment of a fibrous bioink composed of alginate hydrogel, polylactic acid…

In situ forming collagen–hyaluronic acid membrane structures: mechanism of self-assembly and applications in regenerative medicine

Acta Biomaterialia 2013 Volume 9, Issue 2, Pages 5153–5161

Bioactive, in situ forming materials have the potential to complement minimally invasive surgical procedures and enhance tissue healing. For such biomaterials to be adopted in the clinic, they must be cost-effective, easily handled by the surgeon and have a history of biocompatibility. To this end, we report a novel and facile self-assembling strategy to create membranes and encapsulating structures using collagen and hyaluronic acid (HA). Unlike membranes built by layer-by-layer deposition of oppositely charged biomolecules, the collagen–HA membranes described here form a diffusion barrier upon electrostatic interaction of the oppositely charged biomolecules, which is further driven by osmotic pressure imbalances….

In vivo screening of extracellular matrix components produced under multiple experimental conditions implanted in one animal

Integrative Biology 2013 Volume 5, Pages 889-898

Animal experiments help to progress and ensure safety of an increasing number of novel therapies, drug development and chemicals. Unfortunately, these also lead to major ethical concerns, costs and limited experimental capacity. We foresee a coercion of all these issues by implantation of well systems directly into vertebrate animals. Here, we used rapid prototyping to create wells with biomaterials to create a three-dimensional (3D) well-system that can be used in vitro and in vivo. First, the well sizes and numbers were adjusted for 3D cell culture and in vitro screening of molecules. Then, the functionality of the wells was evaluated…

Comparison of bacterial adhesion and cellular proliferation on newly developed three-dimensional scaffolds manufactured by rapid prototyping technology

Journal of Biomedical Materials Research Part A 2011 Volume 98A, Issue 2, pages 303-311

Scaffolds used in the field of tissue engineering should facilitate the adherence, spreading, and ingrowth of cells as well as prevent microbial adherence. For the first time, this study simultaneously deals with microbial and tissue cell adhesion to rapid prototyping-produced 3D-scaffolds. The cell growth of human osteosarcoma cells (CAL-72) over a time period of 3-11 days were examined on three scaffolds (PLGA, PLLA, PLLA-TCP) and compared to the adhesion of salivary microorganisms and representative germs of the oral flora (Porphyromonas gingivalis, Prevotella nigrescens, Candida albicans, Enterococcus faecalis, Streptococcus mutans, and Streptococcus sanguinis). Scanning electron microscopy (SEM), cell proliferation measurements, and…

Design and Dynamic Culture of 3D Scaffolds for Cartilage Tissue Engineering

Journal of Biomaterials Applications 2009

Engineered scaffolds for tissue-engineering should be designed to match the stiffness and strength of healthy tissues while maintaining an interconnected pore network and a reasonable porosity. In this work, we have used 3D-ploting technique to produce poly-LLactide (PLLA) macroporous scaffolds with two different pore sizes. The ability of these macroporous scaffolds to support chondrocyte attachment and viability were compared under static and dynamic loading in vitro. Moreover, the 3D-plotting technique was combined with porogen-leaching, leading to micro/macroporous scaffolds, so as to examine the effect of microporosity on the level of cell attachment and viability under similar loading condition. Canine chondrocytes…

Design and Fabrication of 3D Porous Scaffolds to Facilitate Cell-Based Gene Therapy

Tissue Engineering Part A 2008 Volume: 14 Issue 6, Pages 1037-1048

Biomaterials capable of efficient gene delivery by embedded cells provide a fundamental tool for the treatment of acquired or hereditary diseases. A major obstacle is maintaining adequate nutrient and oxygen diffusion to cells within the biomaterial. In this study, we combined the solid free-form fabrication and porogen leaching techniques to fabricate three-dimensional scaffolds, with bimodal pore size distribution, for cell-based gene delivery. The objective of this study was to design micro-/macroporous scaffolds to improve cell viability and drug delivery. Murine bone marrow-derived mesenchymal stromal cells (MSCs) genetically engineered to secrete erythropoietin (EPO) were seeded onto poly-l-lactide (PLLA) scaffolds with different…