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Polylactic Acid

Taiga Wakabayashi, Hiroshi Yagi, Kazuki Tajima, Kohei Kuroda, Masahiro Shinoda, Minoru Kitago, Yuta Abe, Go Oshima, Kazuya Hirukawa, Osamu Itano, Yuko Kitagawa
BACKGROUND: During minimally invasive surgery, efficient and nontoxic hemostats are important for difficult to access bleeding areas. Polylactic acid is an ecofriendly hemostatic agent and we aimed to evaluate the efficacy of a polylactic acid nonwoven fabric (PLAF) developed by Toray Industries, Inc, on liver hemostasis in a preclinical study. MATERIALS AND METHODS: PLAF consists of both 1-µm diameter fibers and 100-µm diameter beaded fibers. Four rats were used, and 2 trough-shaped resections of the liver parenchyma were performed (n = 8 lobes)...
March 21, 2019: Surgical Innovation
Eduardo D Martínez, Carlos D S Brites, Luís D Carlos, Ricardo R Urbano, Carlos Rettori
Upconversion is a non-linear optical phenomenon by which low energy photons stimulate the emission of higher energy ones. Applications of upconversion materials are wide and cover diverse areas such as bio-imaging, solar cells, optical thermometry, displays, and anti-counterfeiting technologies, among others. When these materials are synthesized in the form of nanoparticles, the effect of temperature on the optical emissions depends critically on their size, creating new opportunities for innovation. However, it remains a challenge to achieve upconversion materials that can be easily processed for their direct application or for the manufacture of optoelectronic devices...
2019: Frontiers in Chemistry
Yota Tsuge, Naoto Kato, Shogo Yamamoto, Masako Suda, Toru Jojima, Masayuki Inui
Strain development is critical for microbial production of bio-based chemicals. The stereo-complex form of polylactic acid, a complex of poly-L- and poly-D-lactic acid, is a promising polymer candidate due to its high thermotolerance. Here, we developed Corynebacterium glutamicum strains producing high amounts of L- and D-lactic acid through intensive metabolic engineering. Chromosomal overexpression of genes encoding the glycolytic enzymes, glucokinase, glyceraldehyde-3-phosphate dehydrogenase, phosphofructokinase, triosephosphate isomerase, and enolase, increased L- and D-lactic acid concentration by 146% and 56%, respectively...
March 15, 2019: Applied Microbiology and Biotechnology
Mehdi Ranjbar, Payam Khazaeli, Abbas Pardakhty, Batool Tahamipour, Arezou Amanatfard
The main aim of this study is to synthesize and prepare polyacrylamide (PAM)/polylactic acid (PLA) co-assembled core/shell nanofibers in order to investigate an effective dapsone-loaded capability and dapsone-release in the aqueous medium. Dapsone (4,4-diamino-diphenyl sulfone) has high permeability and low solubility in water. In vitro release testing indicates that maximum incorporation of the dapsone nanoemulsions into core/shell nanofibrous structures were 77.71 after 400 min. Products were characterized with X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo-Gravimetric Analysis (TGA), Dynamic light scattering (DLS) analysis, Contact Angle Measurement (CAM) and nitrogen adsorption [i...
December 2019: Artificial Cells, Nanomedicine, and Biotechnology
Mohammed Al-Rubaiai, Thassyo Pinto, Chunqi Qian, Xiaobo Tan
The field of soft robotics has seen increasing interest and developments in recent years. Stiffness tuning is a desirable characteristic for soft robots since it enables adaptively modulating the load-bearing capability, shape, and locomotion behavior of the robots. In this article a compact and cost-effective mechanism for stiffness tuning is proposed based on a three-dimensional printed conductive polylactic acid (CPLA) material, and its potential in soft robotics is demonstrated through a soft pneumatic actuator (SPA) capable of stiffness and shape modulation...
March 11, 2019: Soft Robotics
Omar Qutachi, Anthony J Bullock, Giulia Gigliobianco, Sheila MacNeil
While vascular endothelial growth factor (VEGF) is an acknowledged potent pro-angiogenic agent there is a need to deliver it at an appropriate concentration for several days to achieve angiogenesis. The aim of this study was to produce microspheres of biodegradable polylactic-co-glycolic acid (PLGA) tailored to achieve sustained release of VEGF at an appropriate concentration over seven days, avoiding excessive unregulated release of VEGF that has been associated with the formation of leaky blood vessels. Several formulations were examined to produce microspheres loaded with both human serum albumin (HSA) and VEGF to achieve release of VEGF between 3 and 10 ng per ml for seven days to match the therapeutic window desired for angiogenesis...
March 7, 2019: International Journal of Pharmaceutics
Ming Li Tan, Min Zhang, Feng Li, Fernando Maya, Michael C Breadmore
A concentric electromembrane extraction preconcentration device was designed and fabricated using fused deposition modelling 3D printing. The device consisted of a hemispherical electrode sample vial printed from a filament of conductive polylactic acid (PLA), into which sat a smaller hemispherical 3D printed porous membrane acceptor vial. Application of voltage between a point-electrode placed in the center of 20 μL solution inside the acceptor vial and the electrode vial containing 1 mL of sample, enabled anion migration through the 3D printed porous material into the acceptor solution...
February 22, 2019: Journal of Chromatography. A
Imke Rudnik-Jansen, Karin Schrijver, Nina Woike, Anna Tellegen, Sabine Versteeg, Pieter Emans, George Mihov, Jens Thies, Niels Eijkelkamp, Marianna Tryfonidou, Laura Creemers
Inflammation of the synovium and joint capsule is a main driver of pain in an osteoarthritic (OA) joint. Triamcinolone acetonide (TAA) is a classical corticosteroid that reduces synovitis and alleviates pain, albeit transiently. Biomaterial-based local TAA release may prolong the suppression of pain without the need for multiple injections. Polylactic-co-glycolic acid (PLGA) formulations of TAA prolong OA pain relief to a limited extent. A novel polyesteramide (PEA) microsphere platform allows for extended release in the OA joint for over 3 months...
December 2019: Drug Delivery
Shibing Shan, Jingchun Yao, Lisa Xu, Shangcong Han, Jie Cao, Guimin Zhang, Yong Sun
Icaritin is an active ingredient derived from the plant Herba Epimedium, which exhibits various pharmacological and biological activities. However, icaritin has solubility in water of less than 1.0 μ g/ml and the low aqueous solubility hampered its use as a therapeutic agent. In this work, as shown in Scheme 1, we synthesized a series of mPEG-PLA (Methyl poly (ethylene glycol)-Polylactic acid) with different hydrophilic and hydrophobic segment ratios via ring-opening polymerization and prepared mPEG-PLA/icaritin micelles by solid dispersion method to improve the solubility of icaritin...
April 1, 2019: Journal of Biomedical Nanotechnology
Wen Shen, Guanghua Zhang, Xuemei Ge, Yali Li, Guodong Fan
Polylactic electrospun porous fibres have been widely used in tissue engineering scaffolds. However, the application of linear polylactic is limited due to its poor hydrophilicity, which leads to phase separation and has been seldom used in porous fibre preparation. Instead, branching polylactic acts as a new effective method to prepare porous fibres because it can increase polylactic polar property and make it easy to be formulated in the following application. In the current study, we prepared an ultra-high molecular weight of high branching polylactic with glycerol as the initiator by controlling the ring-opening polymerization time, adding amount of catalyst and glycerol...
September 2018: Royal Society Open Science
Lauren J Delaney, Daniel MacDonald, Jay Leung, Keith Fitzgerald, Alex M Sevit, John R Eisenbrey, Neil Patel, Flemming Forsberg, Christopher K Kepler, Taolin Fang, Steven M Kurtz, Noreen J Hickok
Despite aggressive peri-operative antibiotic treatments, up to 10% of patients undergoing instrumented spinal surgery develop an infection. Like most implant-associated infections, spinal infections persist through colonization and biofilm formation on spinal instrumentation, which can include metal screws and rods for fixation and an intervertebral cage commonly comprised of polyether ether ketone (PEEK). We have designed a PEEK antibiotic reservoir that would clip to the metal fixation rod and that would achieve slow antibiotic release over several days, followed by a bolus release of antibiotics triggered by ultrasound (US) rupture of a reservoir membrane...
February 28, 2019: Acta Biomaterialia
Iulian Antoniac, Diana Popescu, Aurelian Zapciu, Aurora Antoniac, Florin Miculescu, Horatiu Moldovan
The main objective of this research is to prove the viability of obtaining magnesium (Mg) filled polylactic acid (PLA) biocomposites as filament feedstock for material extrusion-based additive manufacturing (AM). These materials can be used for medical applications, thus benefiting of all the advantages offered by AM technology in terms of design freedom and product customization. Filaments were produced from two PLA + magnesium + vitamin E (α-tocopherol) compositions and then used for manufacturing test samples and ACL (anterior cruciate ligament) screws on a low-cost 3D printer...
March 1, 2019: Materials
Mehdi Ranjbar, Abbas Pardakhty, Batool Tahmipour, Iman Mohamadzadeh
In this study, for the first time, calcium oxide (CaO)/polylactic acid nanoscaffolds were synthesized by co-precipitation assistant reverse micelles method. The physical and chemical (physicochemical) properties of the structures as dental resin composites were also studied. Nanocomposite materials as primary and basic dental compounds can be conveniently applied as dental filling materials with a high esthetic quality. In this research nanoscaffolds act as a bed for nanoparticles and improve the mechanical and chemical (mechanochemical) properties, CaO nanoparticles were loading in polylactic acid nanoscaffold as a bioactivity polymer for usage in the dental resin composites...
February 27, 2019: Luminescence: the Journal of Biological and Chemical Luminescence
Yongfeng Li, Qingjun Ding, Hongyuan Zhao, Tingting Wu, Mingming Zhang, Yaqi Zhang
Anisotropic materials are important functional materials in many fields. The use of these materials is currently being expanded through the rapid development of additive manufacturing. However, there is still no universal method for fabricating two-dimensional anisotropic polymer composites. Here, polylactic acid⁻carbon fiber composites were prepared using the droplet spray method, and their mechanical and friction properties were studied. The tensile strength in the X⁻Y plane perpendicular to the direction of the droplet spray was significantly higher than that in the direction of droplet ejection...
February 23, 2019: Materials
Stefan Julmi, Ann-Kathrin Krüger, Anja-Christina Waselau, Andrea Meyer-Lindenberg, Peter Wriggers, Christian Klose, Hans Jürgen Maier
Large bone defects or fractures must be treated with an implant or transplant. Resorbable implants are attractive as these require only one surgery, whereas bone autografts, which can be cut off from the same person's hip, require more than one procedure. Moreover, porous structures promote the ingrowth of the patient's bone. Thus, the objective of the present study was to develop open-pored biodegradable implant structures with different pore sizes that provide for both adequate degradation behaviour and mechanical properties that match with those of bone...
May 2019: Materials Science & Engineering. C, Materials for Biological Applications
Mirae Kim, Jae Hwan Jeong, Jong-Young Lee, Andrea Capasso, Francesco Bonaccorso, Seok-Hyeon Kang, Young Kook Lee, Gwan-Hyoung Lee
The advent of 3D printing has had a disruptive impact in manufacturing and can potentially revolutionize industrial fields. Thermoplastic materials printable into complex structures are widely employed for 3D printing. Polylactic acid (PLA) is among the most promising polymers used for 3D printing, owing to its low cost, bio-degradability, and non-toxicity. However, PLA is electrically insulating and mechanically weak; this limits its use in a variety of 3D-printing applications. This study demonstrates a straightforward and environment-friendly method to fabricate conductive and mechanically reinforced PLA composites by incorporating graphene nanoplatelets (GNPs)...
February 27, 2019: ACS Applied Materials & Interfaces
Xiao Han, Kaiming Huang, Hongzhi Tang, Jun Ni, Jiongqin Liu, Ping Xu, Fei Tao
Optically pure d-lactate production has received much attention for its critical role in high-performance polylactic acid production. However, the current technology can hardly meet the comprehensive demand of industrialization on final titer, productivity, optical purity, and raw material costs. Here, an efficient d-lactate producer strain, Sporolactobacillus terrae HKM-1, was isolated for d-lactate production. Strain HKM-1 shows extremely high d-lactate fermentative capability by using peanut meal, soybean meal or corn steep liquor powder as a sole nitrogen source; the final titers (205...
February 27, 2019: Biotechnology Journal
Adil Ajmal, Ammon Meskarzadeh, Natalja Genina, Cosima Hirschberg, Johan Peter Boetker, Jukka Rantanen
Development of new product design principles is crucial for obtaining pharmaceutical products with controlled functionality. Four different molds were designed using a computer-aided design (CAD) software and 3D printed with polylactic acid (PLA). A hydroxypropyl methylcellulose (HPMC) and polyethylene glycol (PEG)-based formulation containing indomethacin as the active pharmaceutical ingredient (API) was casted into the molds. Each mold produced a tablet that was designed to disintegrate into a defined number of sections (2, 4, and 6)...
February 26, 2019: AAPS PharmSciTech
Shuwei Shen, Haili Wang, Yingjie Qu, Kuiming Huang, Guangli Liu, Zexin Chen, Canzhen Ma, Pengfei Shao, Jin Hong, Paul Lemaillet, Erbao Dong, Ronald X Xu
Phantoms simulating polarization characteristics of soft tissue play an important role in the development, calibration, and validation of diagnostic polarized imaging devices and of therapeutic strategy, in both laboratory and clinical settings. We propose to fabricate optical phantoms that simulate polarization characteristics of dense fibrous tissues by bonding electrospun polylactic acid (PLA) fibers between polydimethylsiloxane (PDMS) substrate with a groove. Increasing the rotational speed of an electrospinning collector helps improve the orientation of the electrospun fibers...
February 1, 2019: Biomedical Optics Express
Luigi Canullo, Mauro Tronchi, Shunsuke Kawakami, Takahisa Iida, Luca Signorini, Lorenzo Mordini
Systematic reviews showed possible esthetic complications with the use of traditional flap designs after guided bone regeneration (GBR) procedures in the esthetic zone and the aim of this case series was to analyze hard and soft tissue changes over 18 months after these procedures. Healthy subjects requiring tooth extraction and single-implant placement in the anterior maxilla were enrolled in the study. Three months after tooth extraction and ridge preservation, a prosthetic-driven implant was placed. The horizontal bone deficiency was treated with a resorbable bone graft substitute (beta tricalcium phosphate [β-TCP]) and a bioresorbable polylactic acid (PLA) membrane...
March 2019: International Journal of Periodontics & Restorative Dentistry
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