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1.
Artif Organs ; 44(8): 877-882, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32320080

ABSTRACT

The polymer poly(ε-caprolactone) (PCL) has been used in the biomaterial field for its relatively inexpensive price and suitability for modification. Also, its chemical and biological properties are desirable for biomedical applications. The electrospinning process has been used for producing polymer fibers of PCL due in large part to an increased interest in nanoscale properties and technologies. Moreover, the use of biocompatible polymers for the viability of cell growth is a promising alternative to improve osseointegration. Characterization techniques such as scanning electron microscopy and contact angle were used for analyses of samples. Adult human dermal fibroblasts (neonatal) were utilized to evaluate the biocompatibility of the association of the electrospinning process of the biocompatible polymer (PCL) with TiO2 nanotubes on the Ti-30Ta alloy surface. The results of this study showed a favorable response for adhesion on the surface. This promising material is due to the modulation of the biological response.


Subject(s)
Fibroblasts/drug effects , Nanofibers , Nanotubes , Tantalum , Titanium/pharmacology , Alloys , Biocompatible Materials , Caproates , Humans , Lactones , Materials Testing/methods , Microscopy, Electron, Scanning , Polymers , Skin/cytology , Skin/drug effects , Titanium/chemistry
2.
Article in English | WPRIM (Western Pacific) | ID: wpr-1010441

ABSTRACT

The rapid developments of science and technology in China over recent decades, particularly in biomedical research, have brought forward serious challenges regarding ethical governance. Recently, Jian-kui HE, a Chinese scientist, claimed to have "created" the first gene-edited babies, designed to be naturally immune to the human immunodeficiency virus (HIV). The news immediately triggered widespread criticism, denouncement, and debate over the scientific and ethical legitimacy of HE's genetic experiments. China's guidelines and regulations have banned germline genome editing on human embryos for clinical use because of scientific and ethical concerns, in accordance with the international consensus. HE's human experimentation has not only violated these Chinese regulations, but also breached other ethical and regulatory norms. These include questionable scientific value, unreasonable risk-benefit ratio, illegitimate ethics review, invalid informed consent, and regulatory misconduct. This series of ethical failings of HE and his team reveal the institutional failure of the current ethics governance system which largely depends on scientist's self-regulation. The incident highlights the need for urgent improvement of ethics governance at all levels, the enforcement of technical and ethical guidelines, and the establishment of laws relating to such bioethical issues.


Subject(s)
Female , Humans , Infant, Newborn , Pregnancy , CRISPR-Cas Systems , China , Consent Forms/ethics , Ethics, Medical , Gene Editing/legislation & jurisprudence , Gene Knockout Techniques/ethics , HIV Infections/prevention & control , Human Experimentation/legislation & jurisprudence , Professional Misconduct/ethics , Receptors, CCR5/genetics
3.
J Biomed Mater Res B Appl Biomater ; 106(5): 1964-1975, 2018 07.
Article in English | MEDLINE | ID: mdl-28963863

ABSTRACT

Despite their overall success, different blood-contacting medical devices such as heart valves, stents, and so forth, are still plagued with hemocompatibility issues which often result in the need for subsequent replacement and/or life-long anticoagulation therapy. Consequently, there is a significant interest in developing biomaterials that can address these issues. Polymeric-based materials have been proposed for use in many applications due to their ability to be finely tuned through manufacturing and surface modification to enhance hemocompatibility. In this study, we have developed a novel, hydrophilic biomaterial comprised of an interpenetrating polymer network (IPN) of hyaluronan (HA) and linear low density polyethylene (LLDPE). HA is a highly lubricous, anionic polysaccharide ubiquitously found in the human body. It is currently being investigated for a vast array of biomedical applications including cardiovascular therapies such as hydrogel-based regenerative cell therapies for myocardial infarction, HA-coated stents, and surface modifications of polyurethane and metals for use in blood-contacting implants. The aim of this study was to assess the in vitro thrombogenic response of the hydrophilic polymer surface, HA-LLDPE for future potential use as flexible heart valve leaflets. The results indicate that HA-LLDPE is non-toxic and reduces thromobogenicity as compared to LLDPE surfaces, asserting its feasibility for use as a blood-contacting biomaterial. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1964-1975, 2018.


Subject(s)
Biocompatible Materials , Blood Platelets/metabolism , Hyaluronic Acid , Materials Testing , Platelet Aggregation/drug effects , Polyethylene , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Humans , Hyaluronic Acid/chemistry , Hyaluronic Acid/pharmacology , Hydrophobic and Hydrophilic Interactions , Polyethylene/chemistry , Polyethylene/pharmacology , Polyurethanes/chemistry , Polyurethanes/pharmacology , Prostheses and Implants
4.
ACS Biomater Sci Eng ; 3(1): 68-77, 2017 Jan 09.
Article in English | MEDLINE | ID: mdl-33429688

ABSTRACT

The endothelial glycocalyx lining the inside surfaces of blood vessels has multiple features that prevent inflammation, blood clot formation, and infection. This surface represents the highest standard in blood compatibility for long-term contact with blood under physiological flow rates. Engineering materials used in blood-contacting biomedical devices, including metals and polymers, have undesirable interactions with blood that lead to failure modes associated with inflammation, blood clotting, and infection. Platelet adhesion and activation are key events governing these undesirable interactions. In this work, we propose a new surface modification to titanium with three features inspired by the endothelial glcyocalyx: First, titanium surfaces are anodized to produce titania nanotubes with high surface area. Second, the nanostructured surfaces are coated with heparin-chitosan polyelectrolyte multilayers to provide glycosaminoglycan functionalization. Third, chitosan is modified with a nitric oxide-donor chemistry to provide an important antithrombotic small-molecule signal. We show that these surfaces are nontoxic with respect to platelets and leukocytes. The combination of glycocalyx-inspired features results in a dramatic reduction of platelet and leukocyte adhesion and platelet activation.

5.
J Sports Sci Med ; 15(3): 492-500, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27803628

ABSTRACT

The purpose of the study was to determine the effects of 8 weeks of jump squat training on isometric half squat maximal force production (Fmax) and rate of force development over 100ms (RFD100), countermovement jump (CMJ) and squat jump (SJ) height, and 50 m sprint time in moderately trained men. Sixty eight subjects (~21 years, ~180 cm, ~75 kg) were divided into experimental (EXP; n = 36) and control (CON, n = 32) groups. Tests were completed pre-, mid- and post-training. EXP performed jump squat training 3 times per week using loads that allowed all repetitions to be performed with ≥90% of maximum average power output (13 sessions with 4 sets of 8 repetitions and 13 sessions with 8 sets of 4 repetitions). Subjects were given real-time feedback for every repetition during the training sessions. Significant improvements in Fmax from pre- to mid- (Δ ~14%, p<0.001), and from mid- to post-training (Δ ~4%, p < 0.001) in EXP were observed. In CON significantly enhanced Fmax from pre- to mid-training (Δ ~3.5%, p < 0.05) was recorded, but no other significant changes were observed in any other test. In RFD100 significant improvements from pre- to mid-training (Δ ~27%, p < 0.001), as well as from mid- to post-training (Δ ~17%, p < 0.01) were observed. CMJ and SJ height were significantly enhanced from pre- to mid-training (Δ ~10%, ~15%, respectively, p < 0.001) but no further changes occurred from mid- to post-training. Significant improvements in 50 m sprint time from pre- to mid-training (Δ -1%, p < 0.05), and from mid- to post-training (Δ -1.9%, p < 0.001) in EXP were observed. Furthermore, percent changes in EXP were greater than changes in CON during training. It appears that using jump squats with loads that allow repetitions to be performed ≥90% of maximum average power output can simultaneously improve several different athletic performance tasks in the short-term.

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