scholarly journals Multifactorial Effects of Gelling Conditions on Mechanical Properties of Skin-Like Gelatin Membranes Intended for In Vitro Experimentation and Artificial Skin Models

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1991
Author(s):  
Lilian C. Alarcón-Segovia ◽  
Jorge I. Daza-Agudelo ◽  
Ignacio Rintoul
Keyword(s):  
Mechanical Properties ◽  
Wound Care ◽  
Sol Gel ◽  
Cosmetic Products ◽  
Synthesis Conditions ◽  
Skin Contact ◽  
Alternative Materials ◽  
Different Types

The development of new cosmetic products, skin contact medical devices, skin medicaments, wound care devices, tattooing and piercing has experienced an impressive growth in recent years. In parallel, new restrictions to in vivo experimentation in animals and humans have been widely implemented by regulatory authorities. New knowledge about alternative materials for in vitro skin-related experimentation is required to overcome these severe limitations. This paper presents a set of three 4-D surface response equations describing the mechanical properties of skin-like gelatin membranes intended for use as an alternative biomaterial for in vitro skin-related experimentation. The membranes were obtained by a sol-gel method. The novelty of this contribution is the establishment of the cross-dependency effects of key synthesis conditions on the final mechanical properties of gelatin membranes. The results of this work are useful to produce gelatin membranes with tailored mechanical properties mimicking different types of human skins. In particular, membranes with Young’s modulus of 1 MPa and maximum tensile strength of 0.85 MPa were obtained.

Effects of Sterilization on Implant Mechanical Property and Biocompatibility

2005 ◽  
Vol 28 (11) ◽  
pp. 1126-1137 ◽  
Author(s):  
Y.H. An ◽  
F.I. Alvi ◽  
Q. Kang ◽  
M. Laberge ◽  
M.J. Drews ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Biological Effects ◽  
Tissue Response ◽  
Different Types ◽  
Biocompatibility Testing ◽  
Supercritical Phase ◽  
Surface Chemistries

This article concisely reviews the effects of sterilization on the mechanical properties and surface chemistries of implantable biomaterials. This article also summarizes the biological effects of the sterilization-related changes in the implant. Because there are so many different types of implant materials currently in use (including metals, polymers, and diverse biological materials), the response of tissue to these different materials varies dramatically. This review further discusses the effects of sterilization on in vivo and in vitro tissue response specifically to implantable metals and polyethylene, with the possibility of future biocompatibility testing of the implants sterilized with supercritical phase carbon dioxide sterilization.

scholarly journals In VitroandIn VivoEvaluation of Sol-Gel Derived TiO2Coatings Based on a Variety of Precursors and Synthesis Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Krzysztof Marycz ◽  
Justyna Krzak ◽  
Wiktor Urbański ◽  
Celina Pezowicz
Keyword(s):  
Stainless Steel ◽  
Sol Gel ◽  
Biological Response ◽  
Dip Coating ◽  
Elemental Distribution ◽  
Stainless Steel 316L ◽  
Synthesis Conditions ◽  
Cells Cultured

The effect of synthesis way of TiO2coatings on biocompatibility of transplanted materials using anin vitroandin vivorat model was investigated. TiO2layers were synthesized by a nonaqueous sol-gel dip-coating method on stainless steel 316L substrates applying two different precursors and their combination. Morphology and topography of newly formed biomaterials were determined as well as chemical composition and elemental distribution of a surface samples.In vitrotests were conducted by adipose-derived mesenchymal stem cells cultured on TiO2coatings and stainless steel without coatings to assess the bioreactivity of obtained materials. A positive biological effect of TiO2/316L/1 coatings—based on titanium(IV) ethoxide—was found in bothin vitroandin vivomodels. The TiO2/316L/1 exhibited the highest roughness and the lowest titanium concentration in TiO2than TiO2/316L/2—based on titanium(IV) propoxide and TiO2/316L/3—based on both above-mentioned precursors. The proper fibroblast-like morphology and higher proliferation rate of cells cultured on TiO2/316L/1 were observed when compared to the other biomaterials. No inflammatory response in the bone surrounding implant covered by each of the obtained TiO2was present. Our results showed that improvement of routinely used stainless steel 316L with TiO2/316L/1 layer can stimulate beneficial biological response.

scholarly journals Design of PEGylated Three Ligands Silica Nanoparticles for Multi-Receptor Targeting

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 177
Author(s):  
Manon Maurel ◽  
Titouan Montheil ◽  
Julie Martin ◽  
Line Chaar ◽  
Veronica Guzman-Gonzalez ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Sol Gel ◽  
Magic Bullet ◽  
Different Types ◽  
One Step ◽  
Additional Level ◽  
The Stability ◽  
Original Concept

The synthesis of silica nanoparticles (SiNPs) decorated on their surface with a range of various elements (e.g., ligands, drugs, fluorophores, vectors, etc.) in a controlled ratio remains a big challenge. We have previously developed an efficient strategy to obtain in one-step, well-defined multifunctional fluorescent SiNPs displaying fluorophores and two peptides ligands as targeting elements, allowing selective detection of cancer cells. In this paper, we demonstrate that additional level of controlled multifunctionality can be achieved, getting even closer to the original concept of “magic bullet”, using solely sol–gel chemistry to achieve conjugation of PEG chains for stealth, along with three different ligands. In addition, we have answered the recurrent question of the surface ungrafting by investigating the stability of different siloxane linkages with the ERETIC Method (Electronic Reference to Access In Vivo Concentrations) by 19F NMR quantification. We also compared the efficiency of the hybrid silylated fluorophore covalent linkage in the core of the SiNP to conventional methods. Finally, the tumor-cell-targeting efficiency of these multi-ligand NPs on human endothelial cells (HUVEC or HDMEC) and mixed spheroids of human melanoma cells and HUVEC displaying different types of receptors were evaluated in vitro.

Tantalum Oxide Nanoparticles as Versatile Contrast Agents for X-ray Computed Tomography

2020 ◽  
Author(s):  
Shatadru Chakravarty ◽  
Jeremy Hix ◽  
Kaitlyn Wieweora ◽  
Maximilian Volk ◽  
Elizabeth Kenyon ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Contrast Agents ◽  
Mesoporous Silica Nanoparticles ◽  
Sol Gel ◽  
Tantalum Oxide ◽  
High Signal ◽  
Drug Delivery Vehicles ◽  
X Ray Computed

Here we describe the synthesis, characterization and in vitro and in vivo performance of a series of tantalum oxide (TaOx) based nanoparticles (NPs) for computed tomography (CT). Five distinct versions of 9-12 nm diameter silane coated TaOx nanocrystals (NCs) were fabricated by a sol-gel method with varying degrees of hydrophilicity and with or without fluorescence, with the highest reported Ta content to date (78%). Highly hydrophilic NCs were left bare and were evaluated in vivo in mice for micro-CT of full body vasculature, where following intravenous injection, TaOx NCs demonstrate high CT contrast, circulation in blood for ~ 3 h, and eventual accumulation in RES organs; and following injection locally in the mammary gland, where the full ductal tree structure can be clearly delineated. Partially hydrophilic NCs were encapsulated within mesoporous silica nanoparticles (MSNPs; TaOx@MSNPs) and hydrophobic NCs were encapsulated within poly(lactic-co-glycolic acid) (PLGA; TaOx@PLGA) NPs, serving as potential CT-imagable drug delivery vehicles. Bolus intramuscular injections of TaOx@PLGA NPs and TaOx@MSNPs to mimic the accumulation of NPs at a tumor site produce high signal enhancement in mice. In vitro studies on bare NCs and formuated NPs demonstrate high cytocompatibility and low dissolution of TaOx. This work solidifies that TaOx-based NPs are versatile contrast agents for CT.

scholarly journals Safety Assessment of Polypyrrole Nanoparticles and Spray-Coated Textiles

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1991
Author(s):  
Rossella Bengalli ◽  
Luisa Fiandra ◽  
Claudia Vineis ◽  
Diego Omar Sanchez-Ramirez ◽  
Nuno G. Azoia ◽  
...  
Keyword(s):  
Wound Care ◽  
Antimicrobial Properties ◽  
Spray Coating ◽  
Skin Toxicity ◽  
In Vitro Models ◽  
Skin Contact ◽  
Artificial Sweat ◽  
Coated Fabrics ◽  
Textile Coating

Polypyrrole (PPy) nanoparticles (NPs) are used for the coating of materials, such as textiles, with biomedical applications, including wound care and tissue engineering, but they are also promising antibacterial agents. In this work, PPy NPs were used for the spray-coating of textiles with antimicrobial properties. The functional properties of the materials were verified, and their safety was evaluated. Two main exposure scenarios for humans were identified: inhalation of PPy NPs during spray (manufacturing) and direct skin contact with NPs-coated fabrics (use). Thus, the toxicity properties of PPy NPs and PPy-coated textiles were assessed by using in vitro models representative of the lung and the skin. The results from the materials’ characterization showed the stability of both the PPy NP suspension and the textile coating, even after washing cycles and extraction in artificial sweat. Data from an in vitro model of the air–blood barrier showed the low toxicity of these NPs, with no alteration of cell viability and functionality observed. The skin toxicity of PPy NPs and the coated textiles was assessed on a reconstructed human epidermis model following OECD 431 and 439 guidelines. PPy NPs proved to be non-corrosive at the tested conditions, as well as non-irritant after extraction in artificial sweat at two different pH conditions. The obtained data suggest that PPy NPs are safe NMs in applications for textile coating.

scholarly journals Engineering nucleosomes for generating diverse chromatin assemblies

2021 ◽  
Author(s):  
Zenita Adhireksan ◽  
Deepti Sharma ◽  
Phoi Leng Lee ◽  
Qiuye Bao ◽  
Sivaraman Padavattan ◽  
...  
Keyword(s):  
Dynamic Properties ◽  
Dna Nanostructures ◽  
Macromolecular Assemblies ◽  
Maximum Resolution ◽  
Different Types ◽  
Chromatin Structural ◽  
Dna Fragment

Abstract Structural characterization of chromatin is challenging due to conformational and compositional heterogeneity in vivo and dynamic properties that limit achievable resolution in vitro. Although the maximum resolution for solving structures of large macromolecular assemblies by electron microscopy has recently undergone profound increases, X-ray crystallographic approaches may still offer advantages for certain systems. One such system is compact chromatin, wherein the crystalline state recapitulates the crowded molecular environment within the nucleus. Here we show that nucleosomal constructs with cohesive-ended DNA can be designed that assemble into different types of circular configurations or continuous fibers extending throughout crystals. We demonstrate the utility of the method for characterizing nucleosome compaction and linker histone binding at near-atomic resolution but also advance its application for tackling further problems in chromatin structural biology and for generating novel types of DNA nanostructures. We provide a library of cohesive-ended DNA fragment expression constructs and a strategy for engineering DNA-based nanomaterials with a seemingly vast potential variety of architectures and histone chemistries.

scholarly journals Stem cells and exosomes: promising candidates for necrotizing enterocolitis therapy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ruijie Zeng ◽  
Jinghua Wang ◽  
Zewei Zhuo ◽  
Yujun Luo ◽  
Weihong Sha ◽  
...  
Keyword(s):  
Stem Cells ◽  
Necrotizing Enterocolitis ◽  
Therapeutic Effects ◽  
Beneficial Effects ◽  
Pediatric Diseases ◽  
Gastrointestinal Conditions ◽  
Different Types ◽  
Novel Therapeutic Strategies

AbstractNecrotizing enterocolitis (NEC) is a devastating disease predominately affecting neonates. Despite therapeutic advances, NEC remains the leading cause of mortality due to gastrointestinal conditions in neonates. Stem cells have been exploited in various diseases, and the application of different types of stem cells in the NEC therapy is explored in the past decade. However, stem cell transplantation possesses several deficiencies, and exosomes are considered potent alternatives. Exosomes, especially those derived from stem cells and breast milk, demonstrate beneficial effects for NEC both in vivo and in vitro and emerge as promising options for clinical practice. In this review, the function and therapeutic effects of stem cells and exosomes for NEC are investigated and summarized, which provide insights for the development and application of novel therapeutic strategies in pediatric diseases. Further elucidation of mechanisms, improvement in preparation, bioengineering, and administration, as well as rigorous clinical trials are warranted.

scholarly journals Melatonin in Cancer Treatment: Current Knowledge and Future Opportunities

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2506
Author(s):  
Wamidh H. Talib ◽  
Ahmad Riyad Alsayed ◽  
Alaa Abuawad ◽  
Safa Daoud ◽  
Asma Ismail Mahmod
Keyword(s):  
Clinical Trials ◽  
Current Knowledge ◽  
Biological Activities ◽  
Experimental Studies ◽  
Therapeutic Effects ◽  
Cell Proliferation Inhibition ◽  
Different Types ◽  
Solid Foundation

Melatonin is a pleotropic molecule with numerous biological activities. Epidemiological and experimental studies have documented that melatonin could inhibit different types of cancer in vitro and in vivo. Results showed the involvement of melatonin in different anticancer mechanisms including apoptosis induction, cell proliferation inhibition, reduction in tumor growth and metastases, reduction in the side effects associated with chemotherapy and radiotherapy, decreasing drug resistance in cancer therapy, and augmentation of the therapeutic effects of conventional anticancer therapies. Clinical trials revealed that melatonin is an effective adjuvant drug to all conventional therapies. This review summarized melatonin biosynthesis, availability from natural sources, metabolism, bioavailability, anticancer mechanisms of melatonin, its use in clinical trials, and pharmaceutical formulation. Studies discussed in this review will provide a solid foundation for researchers and physicians to design and develop new therapies to treat and prevent cancer using melatonin.

scholarly journals Injectable non-leaching tissue-mimetic bottlebrush elastomers as an advanced platform for reconstructive surgery

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Erfan Dashtimoghadam ◽  
Farahnaz Fahimipour ◽  
Andrew N. Keith ◽  
Foad Vashahi ◽  
Pavel Popryadukhin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reconstructive Surgery ◽  
Biomedical Applications ◽  
The Body ◽  
Surrounding Tissue ◽  
Curing Time ◽  
Materials Used ◽  
Significant Health

AbstractCurrent materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tuning curing time from minutes to hours, which empowers a broad range of biomedical applications from rapid wound sealing to time-intensive reconstructive surgery. These injectable elastomers support in vitro cell proliferation, while also demonstrating in vivo implant integrity with a mild inflammatory response and minimal fibrotic encapsulation.

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