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https://www.readbyqxmd.com/read/28722126/investigating-the-effect-of-poly-l-lactic-acid-nanoparticles-carrying-hypericin-on-the-flow-biased-diffusive-motion-of-hela-cell-organelles
#1
Rozhin Penjweini, Sarah Deville, Omid Haji Maghsoudi, Kristof Notelaers, Anitha Ethirajan, Marcel Ameloot
OBJECTIVES: In this study, we investigate in human cervical epithelial HeLa cells the intracellular dynamics and the mutual interaction with the organelles of the poly-l-lactic acid nanoparticles (PLLA NPs) carrying the naturally occurring hydrophobic photosensitizer hypericin. METHODS: Temporal and spatiotemporal image correlation spectroscopy was used for the assessment of the intracellular diffusion and directed motion of the nanocarriers by tracking the hypericin fluorescence...
July 19, 2017: Journal of Pharmacy and Pharmacology
https://www.readbyqxmd.com/read/28719857/in-situ-adjuvant-therapy-using-a-responsive-doxorubicin-loaded-fibrous-scaffold-after-tumor-resection
#2
Ziming Yuan, Wei Wu, Zhongwei Zhang, Zhiyong Sun, Ruoyu Cheng, Guoqin Pan, Xuemin Wang, Wenguo Cui
As tumor microenvironment becoming more and more important in tumor study, the acid pH around or in solid tumors drew lots of attentions. And the progress of drug delivery systems made the responsive-release possible. This time, we fabricated a new-type composite electrospun poly (L-lactide) (PLLA) fibrous scaffolds, that blent with the mesoporous silica particles (MSNs). Further more, we used sodium bicarbonate (SB) as acid sensitive agent which was wrapped inside the MSNs. And doxorubicin (DOX) was also wrapped into MSNs in order to achieve a sustained release to inhibit tumors in mice, which mimicked the remnant breast cancer with surgery...
July 1, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28701072/a-novel-biomimetic-composite-substitute-of-plla-gelatin-nanofiber-membrane-for-dura-repairing
#3
Kunxue Deng, Yaya Yang, Yiquan Ke, Chengyi Luo, Man Liu, Yuting Deng, Quan Tian, Yuyu Yuan, Tun Yuan, Tao Xu
OBJECTIVE: Biomimetic design will significantly improve growth and regeneration of dural cells and tissue for better repairing effects and fewer complications in repairing the native dura. This study designed a novel composite, biomimetic substitute based on the characteristics of native dura extracellular matrix. METHODS AND RESULTS: This substitute is expected to rapidly induce cell adhesion, migration, and fast regeneration of neotissue. The material characteristics (contact angle, surface charge, and zeta potential were evaluated), in vitro biological characteristics (cell stretch, connections between cells, cell proliferation) and in vivo tissue regeneration capability of this substitute were evaluated, compared to those of collagen dura substitute, the mostly used dura substitute...
July 12, 2017: Neurological Research
https://www.readbyqxmd.com/read/28685784/%C3%AE-pyridylenolate-zinc-catalysts-for-the-ring-opening-homo-and-copolymerization-of-%C3%AE%C2%B5-caprolactone-and-lactides
#4
Jianliang Bai, Xia Xiao, Yue Zhang, Jianbin Chao, Xia Chen
A family of zinc β-pyridylenolates with varying α,β-substituents has been synthesized. A direct reaction of β-pyridyl ketone ligands with ZnEt2 in toluene afforded dimeric [LZnEt]2 (L = (2-C5H4N)-C(R(1))[double bond, length as m-dash]C(R(2))-O-). X-ray structural data revealed that all the [LZnEt]2 complexes exist as μ-O-bridged dimers in the solid state, although they adopt a different geometry. Each of the [LZnEt]2 complexes is a highly active catalyst for the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) and racemic lactide (rac-LA), respectively...
July 7, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28672962/enhanced-regeneration-of-large-cortical-bone-defects-with-electrospun-nanofibrous-membranes-and-low-intensity-pulsed-ultrasound
#5
Leyi Huang, Youzhi Cai, Honghua Hu, Peng Guo, Zengfeng Xin
Poly-L-lactic acid (PLLA) nanofibrous membranes are widely utilized for tissue regeneration. Low intensity pulsed ultrasound (LIPUS) has been considered as a feasible modality for bone union. The aim of the present study was to investigate the potential synergistic effect of LIPUS and PLLA electrospun nanofibrous membranes on large cortical bone defects in rabbits in vivo. The bilateral rabbit tibia defect model was constructed using 18 adult NZ rabbits and the defect sites were treated with the nanofibrous membranes combined with LIPUS or nanofibrous membranes alone...
July 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28671263/small-cause-large-effect-structural-characterization-of-cutinases-from-thermobifida-cellulosilytica
#6
Doris Ribitsch, Altijana Hromic, Sabine Zitzenbacher, Barbara Zartl, Caroline Gamerith, Alessandro Pellis, Alois Jungbauer, Andrzej Łyskowski, Georg Steinkellner, Karl Gruber, Rupert Tscheliessnig, Enrique Herrero Acero, Georg M Guebitz
We have investigated the structures of two native cutinases from Thermobifida cellulosilytica, namely Thc_Cut1 and Thc_Cut2 as well as of two variants, Thc_Cut2_DM (Thc_Cut2_ Arg29Asn_Ala30Val) and Thc_Cut2_TM (Thc_Cut2_Arg19Ser_Arg29Asn_Ala30Val). The four enzymes showed different activities towards the aliphatic polyester poly(lactic acid) (PLLA). The crystal structures of the four enzymes were successfully solved and in combination with Small Angle X-Ray Scattering (SAXS) the structural features responsible for the selectivity difference were elucidated...
July 3, 2017: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/28666885/sandwich-type-plla-nanosheets-loaded-with-bmp-2-induce-bone-regeneration-in-critical-sized-mouse-calvarial-defects
#7
Kuo-Chin Huang, Fumiko Yano, Yasutaka Murahashi, Shuta Takano, Yoshiaki Kitaura, Song Ho Chang, Kazuhito Soma, Steve W N Ueng, Sakae Tanaka, Kazuhiko Ishihara, Yosuke Okamura, Toru Moro, Taku Saito
To overcome serious clinical problems caused by large bone defects, various approaches to bone regeneration have been researched, including tissue engineering, biomaterials, stem cells and drug screening. Previously, we developed a free-standing biodegradable polymer nanosheet composed of poly(L-lactic acid) (PLLA) using a simple fabrication process consisting of spin-coating and peeling techniques. Here, we loaded recombinant human bone morphogenetic protein-2 (rhBMP-2) between two 60-nm-thick PLLA nanosheets, and investigated these sandwich-type nanosheets in bone regeneration applications...
June 27, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28657452/tuning-of-the-surface-biological-behavior-of-poly-l-lactide-based-composites-by-the-incorporation-of-polyelectrolyte-complexes-for-bone-regeneration
#8
Xuehong Wang, Jie Wei, Jianding Chen, Songchao Tang
Poly(L-lactide)(PLLA)-based composites have been widely used for tissue regeneration. Novel polyelectrolyte complexes (PECs) consisted of carboxymethyl starch sodium (CMS) and chitosan oligosaccharide (COS) was fabricated and evaluated. The results suggested that the CMS/COS-PECs (CC-PECs) distinguished from the original polymers alone, presenting an amorphous structure. Then, the CC-PECs/PLLA composites were prepared by varying the relative amount of CC-PECs in the PLLA-matrix, demonstrated by means of the surface morphology, hydrophilicity, water uptake, in vitro degradability and primary cell responses...
June 28, 2017: Journal of Biomaterials Science. Polymer Edition
https://www.readbyqxmd.com/read/28653337/hardystonite-coated-poly-l-lactide-nanofibrous-scaffold-and-efficient-osteogenic-differentiation-of-adipose-derived-mesenchymal-stem-cells
#9
Banafsheh Tavangar, Shaghayegh Arasteh, Haleh Edalatkhah, Ali Salimi, Ali Doostmohammadi, Ehsan Seyedjafari
In this study, a ceramic-coated nanofibrous scaffold has been fabricated to biomimic the microstructure of natural extracellular matrix and the stiffening inorganic compartment of bone. Poly-l-lactic acid (PLLA) nanofibers were electrospun and exposed to oxygen plasma to induce hydrophilicity and promote ceramic adsorption. Hardystonite (HS), which possesses superior osteoinduction potential over hydroxyapatite, was coated on plasma-treated PLLA nanofibers by drenching the nanofibers in HS suspension. Pure and composite PLLA-based scaffolds were characterized in terms of physical and biological properties...
June 27, 2017: Artificial Organs
https://www.readbyqxmd.com/read/28652916/tunable-delayed-controlled-release-profile-from-layered-polymeric-microparticles
#10
D Dutta, C Fauer, K Hickey, M Salifu, S E Stabenfeldt
Composite microparticles (MPs) with layered architecture, engineered from poly(L-lactic acid) (PLLA) and poly(D,L-lactic-co-glycolic acid) (PLGA), are promising devices for achieving the delayed release of proteins. Here, we build on a water-in-oil-in-oil-in-water emulsion method of fabricating layered MPs with an emphasis on modulating the delay period of the protein release profile. Particle hardening parameters (i.e. polymer precipitation rate and total hardening time) following water-in-oil-in-oil-in-water emulsions are known to affect MP structure such as the core/shell material and cargo localization...
June 21, 2017: Journal of Materials Chemistry. B, Materials for Biology and Medicine
https://www.readbyqxmd.com/read/28641554/future-of-spermatogonial-stem-cell-culture-application-of-nanofiber-scaffolds
#11
Azar Shams, Neda Eslahi, Mansoureh Movahedin, Fariborz Izadyar, Hamidreza Asgari, Morteza Koruji
The spermatogonial stem cells (SSCs) are unique in mammals because they can transmit genetic information from generation to generation and it is of significant importance. In testes, Sertoli cells, peritubular myoid cells, Leydig cells and other interstitial cells contribute to the spermatogonial stem cell "niche". So, creation of niche in in vitro condition that mimics in vivo environment is essential to maintain functional characteristic of SSCs. Nanofiber matrices mimic the architecture and size scale of the natural extracellular matrix (ECM)...
June 22, 2017: Current Stem Cell Research & Therapy
https://www.readbyqxmd.com/read/28636337/thermal-annealing-to-modulate-the-shape-memory-behavior-of-a-biobased-and-biocompatible-triblock-copolymer-scaffold-in-the-human-body-temperature-range
#12
Andrea Merlettini, Matteo Gigli, Martina Ramella, Chiara Gualandi, Michelina Soccio, Francesca Boccafoschi, Andrea Munari, Nadia Lotti, Maria Letizia Focarete
A biodegradable and biocompatible electrospun scaffold with shape memory behavior in the physiological temperature range is here presented. It was obtained starting from a specifically designed, biobased PLLA-based triblock copolymer, where the central block is poly(propylene azelate-co-propylene sebacate) (P(PAz60PSeb40)) random copolymer. Shape memory properties are determined by the contemporary presence of the low melting crystals of the P(PAz60PSeb40) block, acting as switching segment, and of the high melting crystal phase of PLLA blocks, acting as physical network...
July 5, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28636315/fabrication-of-hierarchical-macroporous-biocompatible-scaffolds-by-combining-pickering-high-internal-phase-emulsion-templates-with-three-dimensional-printing
#13
Ting Yang, Yang Hu, Chaoyang Wang, Bernard P Binks
Biocompatible and biodegradable porous scaffolds with adjustable pore structure have aroused increasing interest in bone tissue engineering. Here, we report a facile method to fabricate hierarchical macroporous biocompatible (HmPB) scaffolds by combining Pickering high internal phase emulsion (HIPE) templates with three-dimensional (3D) printing. HmPB scaffolds composed of a polymer matrix of poly(l-lactic acid), PLLA, and poly(ε-caprolactone), PCL, are readily fabricated by solvent evaporation of 3D printed Pickering HIPEs which are stabilized by hydrophobically modified silica nanoparticles (h-SiO2)...
July 12, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28635284/competing-stereocomplexation-and-homocrystallization-of-poly-l-lactic-acid-poly-d-lactic-acid-racemic-mixture-effects-of-miscible-blending-with-other-polymers
#14
Jianna Bao, Xiaojia Xue, Kai Li, Xiaohua Chang, Qing Xie, Chengtao Yu, Pengju Pan
Promoting the stereocomplexation ability of high-molecular-weight poly(l-lactic acid) (PLLA) and poly(d-lactic acid) (PDLA) is an efficient way to improve the thermal resistance of the resulting materials. Herein, we studied the competing crystallization kinetics, polymorphic crystalline structure, and lamellae structure of the PLLA/PDLA component in its miscible blends with poly(vinyl acetate) (PVAc) and proposed a method to improve the stereocomplexation ability of PLLA and PDLA through miscible blending with the other polymer...
July 5, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28631613/repairing-a-bone-defect-with-a-three-dimensional-cellular-construct-composed-of-a-multi-layered-cell-sheet-on-electrospun-mesh
#15
Zhiwei Ren, Shiqing Ma, Le Jin, Zihao Liu, Deping Liu, Xu Zhang, Qing Cai, Xiaoping Yang
In addition to providing maneuverability, electrospun nanofibrous meshes can make excellent supports for constructing flexible cell sheets to regulate cell behavior by nanofiber features. With the target of bone regeneration, herein composite nanofibers with two different fiber arrangements (nestlike, random) were electrospun from a blend solution containing poly(l-lactide) (PLLA) and gelatin (1:1 in weight ratio). Unlike the non-woven morphology in a random nanofibrous mesh, PLLA/gelatin composite nanofibers in the nestlike nanofibrous mesh displayed both non-woven and parallel morphologies...
June 20, 2017: Biofabrication
https://www.readbyqxmd.com/read/28629034/icariin-immobilized-electrospinning-poly-l-lactide-fibrous-membranes-via-polydopamine-adhesive-coating-with-enhanced-cytocompatibility-and-osteogenic-activity
#16
Hua Liu, Wenling Li, Binghong Luo, Xuexing Chen, Wei Wen, Changren Zhou
In this study, icariin (ICA), one of the main active ingredients of Herba Epimedii for osteogenesis, was applied to functionalize electrospinning poly(l-lactide) (PLLA) fibrous membrane via an intermediate layer of polydopamine (PDA) to obtain enhanced cytocompatibility and osteogenic activity. For this purpose, an array of PDA-coated PLLA fibrous membranes (PLLA-0.5PDA, PLLA-1PDA, PLLA-2PDA, PLLA-5PDA) and ICA-modified PLLA-2PDA fibrous membranes (PLLA-2PDA-10ICA, PLLA-2PDA-20ICA, PLLA-2PDA-40ICA) were successively prepared...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28629016/effect-of-stearic-acid-modified-hap-nanoparticles-in-different-solvents-on-the-properties-of-pickering-emulsions-and-hap-plla-composites
#17
Ming Zhang, Ai-Juan Wang, Jun-Ming Li, Na Song
Stearic acid (Sa) was used to modify the surface properties of hydroxyapatite (HAp) in different solvents (water, ethanol or dichloromethane(CH2Cl2)). Effect of different solvents on the properties of HAp particles (activation ratio, grafting ratio, chemical properties), emulsion properties (emulsion stability, emulsion type, droplet morphology) as well as the cured materials (morphology, average pore size) were studied. FT-IR and XPS results confirmed the interaction occurred between stearic acid and HAp particles...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28628686/off-face-usage-of-poly-l-lactic-acid-for-body-rejuvenation
#18
Ahmad Jabbar, Suleima Arruda, Neil Sadick
<p>Injectable soft-tissue augmentation agents have become popular alternatives to surgical procedures for the aging face and body. In contrast to temporary, space-occupying replacement fillers such as collagen-based and hyaluronic acid products, poly-l-lactic acid (PLLA) has been demonstrated to gradually promotes deposition of collagen via a biostimulatory response, with therapeutic effects lasting approximately two years. In 2004, the FDA approved its use for rejuvenation of facial contours secondary to lipoatrophy associated with antiretroviral therapy for HIV infection...
May 1, 2017: Journal of Drugs in Dermatology: JDD
https://www.readbyqxmd.com/read/28627315/bioabsorbable-fixation-screw-for-proximal-interphalangeal-arthrodesis-of-lesser-toe-deformities
#19
Jascha Armin Wendelstein, Peter Goger, Peter Bock, Reinhard Schuh, Priv Doz, Hans-Jörg Trnka
BACKGROUND: Although standard fixation of proximal interphalangeal (PIP) arthrodesis by K-wire is relatively inexpensive and well established, it does have some drawbacks, making newer fixation devices interesting. The aim of this study was to clinically and radiologically assess the operative correction of the lesser toe deformation in the form of a PIP arthrodesis using a bioabsorbable 2.7-mm fixation screw. METHODS: From January 2011 until October 2013, 34 patients underwent a PIP arthrodesis using the TRIM-IT (Arthrex) 2...
June 1, 2017: Foot & Ankle International
https://www.readbyqxmd.com/read/28621889/enhanced-skin-regeneration-by-herbal-extract-coated-poly-l-lactic-acid-nanofibrous-scaffold
#20
Aytak Jouybar, Ehsan Seyedjafari, Abdolreza Ardeshirylajimi, Ali Zandi-Karimi, Nikta Feizi, Mohammad-Mehdi Khani, Iraj Pousti
The wound healing process is directly related to the type of treatment. Existing methods of treatment are not responsive enough for severe wounds. The aim of this study was the potential capacity investigation of poly-L-lactic acid (PLLA) nanofibrous scaffolds coated by aloe vera gel for wound dressing applications. In this study, electrospinning method was used for preparing PLLA nanofibers, and after characterization by SEM and MTT, its influence on the wound healing process was investigated with and without aloe vera gel as a wound dressing in full-thickness skin defect in mice...
June 16, 2017: Artificial Organs
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