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1.
J Biomater Sci Polym Ed ; 35(5): 756-797, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38300215

RESUMEN

Spontaneous bone regeneration encounters substantial restrictions in cases of bone defects, demanding external intervention to improve the repair and regeneration procedure. The field of bone tissue engineering (BTE), which embraces a range of disciplines, offers compelling replacements for conventional strategies like autografts, allografts, and xenografts. Among the diverse scaffolding materials utilized in BTE applications, hydrogels have demonstrated great promise as templates for the regeneration of bone owing to their resemblance to the innate extracellular matrix. In spite of the advancement of several biomaterials, chitosan (CS), a natural biopolymer, has garnered significant attention in recent years as a beneficial graft material for producing injectable hydrogels. Injectable hydrogels based on CS formulations provide numerous advantages, including their capacity to absorb and preserve a significant amount of water, their minimally invasive character, the existence of porous structures, and their capability to adapt accurately to irregular defects. Moreover, combining CS with other naturally derived or synthetic polymers and bioactive materials has displayed its effectiveness as a feasible substitute for traditional grafts. We aim to spotlight the composition, production, and physicochemical characteristics and practical utilization of CS-based injectable hydrogels, explicitly focusing on their potential implementations in bone regeneration. We consider this review a fundamental resource and a source of inspiration for future research attempts to pioneer the next era of tissue-engineering scaffold materials.


Asunto(s)
Quitosano , Humanos , Quitosano/química , Hidrogeles/química , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/química , Andamios del Tejido/química , Ingeniería de Tejidos/métodos , Regeneración Ósea
2.
Bioinorg Chem Appl ; 2023: 1731931, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37125143

RESUMEN

One of the more enticing, ecologically responsible, as well as safe and sustainable methodologies is eco-friendly nanomaterial synthesis. Vegetation materials will be used as reductants instead of toxic substances for synthesising nanoparticles. The current study used Ruellia tuberosa (RT) leaf extract digest to synthesise FeO nanomaterials, which were then characterised using XRD. Following that, microbially produced FeO molecules were mixed with a Kevlar-based polymeric matrix to study the blended consequences. To examine the interbreeding, the current experimental analyses were performed, including both static and dynamic mechanical characteristics. The addition of FeO nanofillers improved the elastic modulus, tensile strength, and storage modulus of the nanocomposite. Impact force uptake has been raised to a certain extent by the addition of nanoparticles. The findings of this research show that incorporating FeO nanofillers into Kevlar fabrics is a promising technique for increasing the mechanical characteristics of hybrid laminated composites. As per DMA evaluation, the sample without nanomaterials had a more volcanic lava response, which is a useful thing for body systems for missile use. Another critical aspect of a nanoparticles-filled nanocomposite that must be addressed is the relatively uniform scattering of padding as well as the development of interfacial adhesion in such a combination. The presence of FeO fillers in polymeric composites is confirmed by XRD analysis.

3.
Oman Med J ; 37(5): e419, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36341003

RESUMEN

Objectives: Non-small cell lung cancer (NSCLC) accounts for 75-85% of all lung cancer diagnoses. This meta-analysis sought to estimate the overall survival (OS) of NSCLC based on randomized control trials which had compared docetaxel with kinase inhibitors, antineoplastic agents, and monoclonal antibodies as second-line chemotherapy for advanced NSCLC. Methods: We selected 18 randomized control trials which used docetaxel as the standard treatment arm, while kinase inhibitors, antineoplastic agents, and monoclonal antibodies constituted the experimental arm. The methodological quality of the trial was classified according to the Modified Jadad score. Several steps were taken to reduce publication bias. A forest plot was used to graphically summarize the meta-analysis. Results: The Hedge's g value of antineoplastic agents was 0.11 (95% CI: -0.03-0.26), while for kinase inhibitors was 0.04 (95% CI: -0.10-0.17) and monoclonal antibodies was 0.05 (95% CI: -0.02-0.13). Forest plot showed a clear though only slightly higher overall survival using docetaxel compared to those of the antineoplastic agents, kinase inhibitors, and monoclonal antibodies, due to the existence of moderate heterogeneity and lower impact. Conclusions: Overall, the patients in these studies who were in the standard (docetaxel) treatment arm had slightly better OS than those in the intervention treatment arm. As per the results, docetaxel was more effective in the second-line treatment of advanced NSCLC than antineoplastic agents, monoclonal antibodies, and kinase inhibitors. We infer that docetaxel-based second-line therapy for patients with advanced NSCLC is supported by our meta-analysis.

4.
J Mater Chem B ; 10(17): 3199-3241, 2022 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-35445674

RESUMEN

Throughout history, natural biomaterials have benefited society. Nevertheless, in recent years, tailoring natural materials for diverse biomedical applications accompanied with sustainability has become the focus. With the progress in the field of materials science, novel approaches for the production, processing, and functionalization of biomaterials to obtain specific architectures have become achievable. This review highlights an immensely adaptable natural biomaterial, bacterial cellulose (BC). BC is an emerging sustainable biopolymer with immense potential in the biomedical field due to its unique physical properties such as flexibility, high porosity, good water holding capacity, and small size; chemical properties such as high crystallinity, foldability, high purity, high polymerization degree, and easy modification; and biological characteristics such as biodegradability, biocompatibility, excellent biological affinity, and non-biotoxicity. The structure of BC consists of glucose monomer units polymerized via cellulose synthase in ß-1-4 glucan chains, creating BC nano fibrillar bundles with a uniaxial orientation. BC-based composites have been extensively investigated for diverse biomedical applications due to their similarity to the extracellular matrix structure. The recent progress in nanotechnology allows the further modification of BC, producing novel BC-based biomaterials for various applications. In this review, we strengthen the existing knowledge on the production of BC and BC composites and their unique properties, and highlight the most recent advances, focusing mainly on the delivery of active pharmaceutical compounds, tissue engineering, and wound healing. Further, we endeavor to present the challenges and prospects for BC-associated composites for their application in the biomedical field.


Asunto(s)
Materiales Biocompatibles , Celulosa , Bacterias/química , Materiales Biocompatibles/química , Celulosa/química , Ingeniería de Tejidos , Cicatrización de Heridas
5.
Sci Rep ; 10(1): 6240, 2020 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-32277138

RESUMEN

Graphene interconnects have been projected to out-perform Copper interconnects in the next generation Magnetic Quantum-dot Cellular Automata (MQCA) based nano-electronic applications. In this paper a simple two-step lithography process for patterning CVD monolayer graphene on SiO2/Si substrate has been used that resulted in the current density of one order higher magnitude as compared to the state-of-the-art graphene-based interconnects. Electrical performances of the fabricated graphene interconnects were evaluated, and the impact of temperature and size on the current density and reliability was investigated. The maximum current density of 1.18 ×108 A/cm2 was observed for 0.3 µm graphene interconnect on SiO2/Si substrate, which is about two orders and one order higher than that of conventionally used copper interconnects and CVD grown graphene respectively, thus demonstrating huge potential in outperforming copper wires for on-chip clocking. The drop in current at 473 K as compared to room temperature was found to be nearly 30%, indicating a positive temperature coefficient of resistivity (TCR). TCR for all cases were studied and it was found that with decrease in width, the sensitivity of temperature also reduces. The effect of resistivity on the breakdown current density was analysed on the experimental data using Matlab and found to follow the power-law equations. The breakdown current density was found to have a reciprocal relationship to graphene interconnect resistivity suggesting Joule heating as the likely mechanism of breakdown.

6.
Sci Rep ; 7(1): 8092, 2017 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-28808250

RESUMEN

Polarization sensitive and insensitive color filters have important applications in the area of nano-spectroscopy and CCD imaging applications. Metallic nanostructures provide an efficient way to design and engineer ultrathin color filters. These nanostructures have capability to split the white light into fundamental colors and enable color filters with ultrahigh resolution but their efficiency can be restricted due to high losses in metals especially at the visible wavelengths. In this work, we demonstrate all-dielectric color filters based on Si nanoantennas, which are sensitive to incident-wave polarization and, thus, tunable with the aid of polarization angle variation. Two different information can be encoded in two different polarization states in one nanostructure. The nanoantenna based pixels are highly efficient and can provide high quality of colors, in particular, due to low losses in Si at optical frequencies. We experimentally demonstrate that a variety of colors can be achieved by changing the physical size of the nonsymmetric cross-shaped nanoantennas. The proposed devices allow to cover an extended gamut of colors on CIE-1931 chromaticity diagram owing to the existence of high-quality resonances in Si nanoantennas. Significant tunability of the suggested color filters can be achieved by varying polarization angle in both transmission and reflection mode. Additional tunability can be obtained by switching between transmission and reflection modes.

7.
Biotechnol Rep (Amst) ; 4: 56-59, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28435801

RESUMEN

Due to lack of morphological methods to identify sex at early stage in the plants with long juvenile period the application of molecular markers is expected to facilitate breeding program. The objective of this study is to identify molecular markers linked to sex determination of the plant Simarouba glauca which assists in crop improvement program. Random amplified polymorphic DNA primers were tested on dioeceious and hermaphrodite plant Simarouba glauca. A set of eighty five RAPD primers were screened out of which only five primers were found to be associated with sex. The primer OPU-10 is male specific and OPD-19 primer is female specific. Another primer OPU-19 produced a unique amplification in only hermaphrodite individuals. Female and hermaphrodite specific primer OPS-05 amplified an amplicon in female and hermaphrodite and was absent in male plant. Primer OPW-03 produced amplicon specific to male and hermaphrodite plants and was absent in female plants.

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