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Polylactic Acid

Xiao-Heng Zhao, Franklin R Tay, Yan-Jun Fang, Liu-Yan Meng, Zhuan Bian
OBJECTIVES: Gingival recession and alveolar bone loss are common manifestations of periodontitis. Periodontal regeneration is the ideal strategy for rehabilitating periodontal tissue defects and preventing tooth loss. The present study examined whether localized, topical application of gingival overgrowth-inducing drugs, phenytoin, nifedipine or cyclosporine, induces periodontal regeneration. METHODS: Polylactic-co-glycolic acid (PLGA) was used as the carrier for preparation of phenytoin, nifedipine or cyclosporine-loaded PLGA microspheres, using an oil-in-water emulsification technique...
October 6, 2018: Archives of Oral Biology
Meiyu Gai, Wenhao Li, Johannes Frueh, Gleb B Sukhorukov
Surface mediated drug delivery is important for a large variety of applications, especially in medicine to control cell growth, prevent blood platelet activation on implants or for self-disinfecting devices (e.g. catheters). In industrial applications, controlled release of substances from surfaces is needed in a broad range of applications from anti-corrosion systems to anti-biofouling. Polyelectrolyte multilayers (PEM) based microcontainers (MCs) require several days production time, while MCs composed out of polylactic acid (PLA) are entirely hydrophobic, offering no functionality...
October 10, 2018: Colloids and Surfaces. B, Biointerfaces
Sophia P Pilipchuk, Tobias Fretwurst, Ning Yu, Lena Larsson, Nolan M Kavanagh, Farah Asa'ad, Kenneth C K Cheng, Joerg Lahann, William V Giannobile
Periodontal disease destroys supporting structures of teeth. However, tissue engineering strategies offer potential to enhance regeneration. Here, the strategies of patterned topography, spatiotemporally controlled growth factor gene delivery, and cell-based therapy to repair bone-periodontal ligament (PDL) interfaces are combined. Micropatterned scaffolds are fabricated for the ligament regions using polycaprolactone (PCL)/polylactic-co-glycolic acid and combined with amorphous PCL scaffolds for the bone region...
October 19, 2018: Advanced Healthcare Materials
Milda Alksne, Egidijus Simoliunas, Migle Kalvaityte, Edvinas Skliutas, Ieva Rinkunaite, Ieva Gendviliene, Daiva Baltriukiene, Vygandas Rutkunas, Virginija Bukelskiene
Topography of the scaffold is one of the most important factors defining the quality of artificial bone. However, the production of precise micro- and nano-structured scaffolds, which is known to enhance osteogenic differentiation, is expensive and time-consuming. Meanwhile, little is known about macro-patterns (larger than cell diameter) effect on cell fate, while this kind of structures would significantly facilitate the manufacturing of artificial skeleton. Therefore, this research is focused on polylactic acid scaffold's macro-pattern impact on rat's dental pulp stem cells (DPSCs) morphology, proliferation, and osteogenic differentiation...
October 19, 2018: Journal of Biomedical Materials Research. Part A
L Peng, Z H Wang, Y C Sun, W Qu, Y Han, Y H Liang
OBJECTIVE: To establish an apicoectomy guide template design and manufacturing method, based on multi-source data fusion, computer aided design (CAD) and fused deposition modeling (FDM). The feasibility of the guide template was preliminary evaluated by the in vitro model experiment. METHODS: An extracted upper anterior tooth, after root canal treatment, was optical scanned, after which the extracted upper anterior tooth was poured in an apicoectomy plaster model...
October 18, 2018: Beijing da Xue Xue Bao. Yi Xue Ban, Journal of Peking University. Health Sciences
Claire I A van Houdt, Paulo R Gabbai-Armelin, Paula M Lopez-Perez, Dietmar J O Ulrich, John A Jansen, Ana Claudia M Renno, Jeroen J J P van den Beucken
Osteoporosis represents a major health problem in terms of compromising bone strength and increasing the risk of bone fractures. It can be medically treated with bisphosphonates, which act systemically upon oral or venous administration. Further, bone regenerative treatments in osteoporotic conditions present a challenge. Here, we focused on the development of a synthetic bone substitute material with local diminishing effects on osteoporosis. Composites were created using calcium phosphate cement (CPC; 60 wt%) and polylactic-co-glycolic acid (PLGA; 40 wt%), which were loaded with alendronate (ALN)...
October 18, 2018: Scientific Reports
Monika E Freiser, Anish Ghodadra, Lindsay Hart, Christopher Griffith, Noel Jabbour
Importance: Three-dimensional (3-D) printing of temporal bones is becoming more prevalent. However, there has been no measure of the safety of drilling these models to date. It is unknown whether the heat and sheer from the drill may create harmful volatile organic compounds (VOCs). Objective: To determine the level of exposure to airborne contaminants when conducting high-speed drilling on 3-D-printed models and to explore whether there is a need for exposure control measures...
September 1, 2018: JAMA Otolaryngology—Head & Neck Surgery
Jing Han, Baojin Ma, Hongrui Liu, Ting Wang, Fang Wang, Chengjia Xie, Minqi Li, Hong Liu, Shaohua Ge
Periodontitis is an inflammatory disease leading to tooth loss, alveolar bone absorption and disorder of masticatory function. Guided tissue regeneration (GTR) is one of the most common strategies for regeneration of lost periodontium. During surgical process, barrier membranes, and osteoinductive/osteoconductive materials should be placed, respectively, which may increase risks of infection, bleeding, and difficulty of operation. Here, we introduced a new kind of hydroxyapatite (HAp) nanowires modified polylactic acid (PLA) membrane to achieve barrier/osteoinduction dual functions...
October 16, 2018: Journal of Biomedical Materials Research. Part A
Bogdanel Silvestru Munteanu, Liviu Sacarescu, Ana-Lavinia Vasiliu, Gabriela Elena Hitruc, Gina M Pricope, Morten Sivertsvik, Jan Thomas Rosnes, Cornelia Vasile
Polylactic acid (PLA) films were coated by coaxial electrospinning with essential and vegetable oils (clove and argan oils) and encapsulated into chitosan, in order to combine the biodegradability and mechanical properties of PLA substrates with the antimicrobial and antioxidant properties of the chitosan⁻oil nanocoatings. It has been established that the morphology of the electrospun nanocoatings mainly depend on the average molecular weight (MW) of chitosan. Oil beads, encapsulated into the main chitosan nanofibers, were obtained using high-MW chitosan (Chit-H)...
October 13, 2018: Materials
Hirofumi Kyutoku, Nanaka Maeda, Hiroki Sakamoto, Hiroyuki Nishimura, Kazushi Yamada
Bio-composites made of polylactic acid (PLA) matrix reinforced with cellulose fibers (CF) were prepared using a twin-screw extruder and injection molding. The CFs were coated with epoxy-based surface treatment agents. Accelerated degradation tests were carried out on these PLA/CF composites at high temperatures (60 °C) or at constant temperature and constant humidity (60 °C/70% RH), and the higher-order structure changes and degradation characteristics of the molded products were evaluated. In the accelerated degradation test at 60 °C, the thermal and mechanical properties of PLA/CF composites showed no degradation, whereas at 60 °C and 70% RH, the melting point decreased ca...
January 1, 2019: Carbohydrate Polymers
Bartolomeo Coppola, Nicola Cappetti, Luciano Di Maio, Paola Scarfato, Loredana Incarnato
In this study, the possibility of using a layered silicate-reinforced polylactic acid (PLA) in additive manufacturing applications was investigated. In particular, the aim of this work was to study the influence of printing temperature in the 3D printing process of PLA/clay nanocomposites. For this reason, two PLA grades (4032D and 2003D, D-isomer content 1.5 and 4, respectively) were melt-compounded by a twin screw extruder with a layered silicate (Cloisite 30B) at 4 wt %. Then, PLA and PLA/clay feedstock filaments (diameter 1...
October 11, 2018: Materials
Sundus Riaz, Nosheen Fatima, Ahmed Rasheed, Mehvish Riaz, Faiza Anwar, Yamna Khatoon
Polylactic acid (PLA) is a biodegradable thermoplastic polyester. In 2010, PLA became the second highest consumed bioplastic in the world due to its wide application. Conventionally, PLA is produced by direct condensation of lactic acid monomer and ring opening polymerization of lactide, resulting in lower molecular weight and lesser strength of polymer. Furthermore, conventional methods of PLA production require a catalyst which makes it inappropriate for biomedical applications. Newer method utilizes metabolic engineering of microorganism for direct production of PLA through fermentation which produces good quality and high molecular weight and yield as compared to conventional methods...
2018: International Journal of Biomaterials
Jean-François Boursier, Alexandre Fournet, Jean Bassanino, Mathieu Manassero, Anne-Sophie Bedu, Dimitri Leperlier
OBJECTIVES:  The main purpose of this study was to determine the reproducibility and accuracy of a three-dimensional (3D) bone model printed on a desktop 3D-printer based on fused deposition modelling (FDM) technology with polylactic acid (PLA) and the effect of autoclave sterilization on the printed models. METHODS:  Computed tomographic images of the tibia were obtained from 10 feline cadavers, used to create a bone surface-rendering file and sent to the 3D printing software...
October 9, 2018: Veterinary and Comparative Orthopaedics and Traumatology: V.C.O.T
Daiana Wischral, Johanna Méndez Arias, Luiz Felipe Modesto, Douglas de França Passos, Nei Pereira
Lactic acid, traditionally obtained through fermentation process, presents numerous applications in different industrial segments, including production of biodegradable polylactic acid (PLA). Development of low cost substrate fermentations could improve economic viability of lactic acid production, through the use of agricultural residues as lignocellulosic biomass. Studies regarding the use of sugarcane bagasse hydrolysates for lactic acid production by Lactobacillus spp. are reported. First, five strains of Lactobacillus spp...
October 8, 2018: Biotechnology Progress
Mahbod Hajighasemi, Anatoli Tchigvintsev, Boguslaw P Nocek, Robert Flick, Ana Popovic, Tran Hai, Anna N Khusnutdinova, Greg Brown, Xiaohui Xu, Hong Cui, Julia Anstett, Tatyana N Chernikova, Thomas Bruls, Denis Le Paslier, Michail M Yakimov, Andrzej Joachimiak, Olga V Golyshina, Alexei Savchenko, Peter N Golyshin, Elizabeth A Edwards, Alexander F Yakunin
The continuous growth of global plastics production, including polyesters, has resulted in increasing plastic pollution and subsequent negative environmental impacts. Therefore, enzyme-catalyzed depolymerization of synthetic polyesters as a plastics recycling approach has become a focus of research. In this study, we screened over 200 purified uncharacterized hydrolases from environmental metagenomes and sequenced microbial genomes and identified at least 10 proteins with high hydrolytic activity against synthetic polyesters...
October 4, 2018: Environmental Science & Technology
María Dolores Samper, David Bertomeu, Marina Patricia Arrieta, José Miguel Ferri, Juan López-Martínez
Recycling polymers is common due to the need to reduce the environmental impact of these materials. Polypropylene (PP) is one of the polymers called 'commodities polymers' and it is commonly used in a wide variety of short-term applications such as food packaging and agricultural products. That is why a large amount of PP residues that can be recycled are generated every year. However, the current increasing introduction of biodegradable polymers in the food packaging industry can negatively affect the properties of recycled PP if those kinds of plastics are disposed with traditional plastics...
October 2, 2018: Materials
Tristan Tham, Keith Roberts, John Shanahan, John Burban, Peter Costantino
Aim: This pilot study describes a novel composite of hydroxyapatite and biodegradable polylactic acid with wax-like handling properties (BoneSeal® ). The goal was to compare quantitative measures of bone healing between BoneSeal versus Bone wax. Materials & methods: BoneSeal and Bone wax were introduced into separate defects of a single porcine specimen. After 6 weeks, the defect sites were harvested for analysis. Results: Both groups had similar hemostatic action...
September 2018: Future Science OA
Zhi Zhou, Qingqiang Yao, Lan Li, Xin Zhang, Bo Wei, Li Yuan, Liming Wang
BACKGROUND The aim of this study was to design and test a novel composite scaffold with antibacterial efficacy for treating bone infections using a three-dimensional (3D) printed poly(ε-caprolactone) (PCL) scaffold coated with polydopamine (PDA) for the adsorption of polylactic acid-glycolic acid (PLGA) microspheres loaded with vancomycin. MATERIAL AND METHODS Vancomycin-loaded PLGA microspheres were produced by the double-emulsion method, and microsphere morphology, drug-loading dosage, encapsulation efficiency, average diameter, and release characteristics were examined...
September 30, 2018: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Rachel B Ger, Daniel F Craft, Dennis S Mackin, Shouhao Zhou, Rick R Layman, A Kyle Jones, Hesham Elhalawani, Clifton D Fuller, Rebecca M Howell, Heng Li, R Jason Stafford, Laurence E Court
Radiomics studies have demonstrated the potential use of quantitative image features to improve prognostic stratification of patients with head and neck cancer. Imaging protocol parameters that can affect radiomics feature values have been investigated, but the effects of artifacts caused by intrinsic patient factors have not. Two such artifacts that are common in patients with head and neck cancer are streak artifacts caused by dental fillings and beam-hardening artifacts caused by bone. The purpose of this study was to test the impact of these artifacts and if needed, methods for compensating for these artifacts in head and neck radiomics studies...
November 2018: Computerized Medical Imaging and Graphics: the Official Journal of the Computerized Medical Imaging Society
Keqin Wu, Jieying Liu, Lei Lei, Yuanyuan Shen, Shengrong Guo
Anti-tumor drug/stent combinations play a dual role of stent and local chemotherapy to cancer. Herein, a series of paclitaxel (PTX) loaded polylactic acid (PLA) stent films were studied on drug release characteristics and in vivo antitumor effects. The film was implanted beneath and released drug towards the subcutaneous PC-3 tumor xenograft in mice, which consisted of a PTX-loaded layer and a drug-free backing layer. The concentrations of PTX were 103-104 times higher than those in normal tissue or organs in 26 days after implantation of the 50% PTX/20% PEG-loaded film, indicating an extreme accumulation of PTX in tumor tissue...
September 26, 2018: International Journal of Pharmaceutics
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