1,720,978 research outputs found
Polymeric Nanohybrids as a New Class of Therapeutic Biotransporters
No full textA possible solution to enhance existing drug and gene therapies is to develop hybrid nanocarriers capable of delivering therapeutic agents in a controlled and targeted manner. This goal can be achieved by designing nanohybrid systems, which combine organic or inorganic nanomaterials with biomacromolecules into a single composite. The unique combination of properties along with their facile fabrication enables the design of smart carriers for both drug and gene delivery. These hybrids can be further modified with cell targeting motifs to enhance their biological interactivity. In this Talents and Trends article, an overview of emerging nanohybrid-based technologies will be provided to highlight their potential use as innovative platforms for improved cancer therapies and new strategies in regenerative medicine. The clinical relevance of these systems will be reviewed to define the current challenges which still need to be addressed to allow these therapies to move from bench to bedside. Polymeric nanohybrids offer a useful platform to deliver drugs and genes in a selective and efficient manner. A variety of nanomaterials can be combined together with biomolecules in order to generate the next generation of biotransporters. This Talent article highlights the diverse innovative solutions in this direction with particular emphasis on the development of new biotransporters for drugs and gene delivery
Characterization of Gel-MA network as a drug carrier for angiogenic growth factors
No full textBACKGROUND & OBJECTIVES:
A smart approach to designing vascularized networks is to implement angiogenic growth factors as the fundamental component during hydrogel scaffold synthesis. The main approach to our research can be summarized in two aims:
• Specific Aim (1): Fabrication and characterization of the biocompatible hydrogel based on methacrylated gelatin (Gel-MA) and alginate using a combination of chemical and ionic crosslinking.
• Specific Aim (2): Assessment of the hydrogel drug delivery properties and its biocompatibility in promoting human umbilical vein endothelial cell (HUVEC) proliferation.
METHODS:
Photochemical hydrogels were synthesized under UV irradiation using Gel-MA in combination with the polysaccharide, alginate. Gel mechanical properties were influenced by different concentrations of CaCl2, in addition to different times of UV irradiation. Frequency sweep and compressive tests were carried out to test hydrogel mechanical properties. HUVECs were used to test hydrogel biocompatibility and drug release properties.
RESULTS:
The presence of alginate in the hydrogel network influenced the mechanical properties by increasing the G’ and the Young Modulus as compared to a single network composed of only GelMA. In addition, the optimized hydrogel was able to control the growth factor release over time according to degree of crosslinking.
DISCUSSION & CONCLUSION:
The network proposed may be applied as coating for medical devices, which will serve as a drug carrier for angiogenic factors.
GRANT SUPPORT:
This project was supported by an Institutional Development Award (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20 GM103418 and P20 GM103638. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of General Medical Sciences or the National Institutes of Health
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Engineering cell instructive dna-nanocomposites for tissue engineering, bio-printing and regenerative medicine
No full textEngineering complex tissues that can enhance native tissue functions holds enormous promise for treating diseased conditions resulting from injuries, aging and diseases. Considerable effort has recently been directed towards the development of hydrogels for 3D printing such complex tissues, as they can mimic the physical, chemical, and biological properties of most biological tissues. However, the utility of available hydrogel bioinks for controlling cellular responses is severely constrained due to limited control over structural stability, printability and suboptimal biocompatibility. Here we describe the design of a new family of nanoengineered DNA polymer-based bioink to control and pattern cell behavior, engineer complex tissue structures, as well as utilize this injectable formulation as a drug delivery platform. Precisely, the hydrogel was designed by combining two different type of networks: Type A is made of interconnections between neighboring DNA strands and Type B consists of ionic interactions between the discotic charged (negative surface charge and positive charge along the edges) silicate nanodisks (nSi) and the DNA backbone (Fig 1A). The nSi was introduced to increase viscosity of DNA hydrogel and improve their shear-thinning (B, C), printability (D), and allograft coating properties with enhanced adhesivity (F)
Development of mechanically tunable gelatin-alginate hydrogel to promote stem cell osteogenic differentiation
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The role of substrate stiffness in stem cell transfection of plasmid DNA using lipid-based nanocarriers
No full textStatement of Purpose: Human adipose-derived stem cells (hASCs) express vascular endothelial growth factor (VEGF) as one of the regulators of their proliferation and differentiation. To enhance the expression of this growth factor in hASCs, non-viral transfection methods such as cationic polymers, lipids, and peptide conjugates are attractive candidates. Aside from the type of carrier, internalization of plasmid DNA encoded for VEGF is also dependent on the elasticity of the cell’s substrate which controls the cytoskeletal remodeling. This study investigates the role of substrate stiffness on non-viral transfection of hASCs with the aim to maximize hASCs expression of VEGF
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