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1.
Int J Biol Macromol ; 267(Pt 1): 131390, 2024 May.
Article in English | MEDLINE | ID: mdl-38582473

ABSTRACT

In recent decades, bio-polymeric nanogels have become a forefront in medical research as innovative in-vivo drug carriers. This study introduces a pH-sensitive chitosan nanoparticles/P(N-Isopropylacrylamide-co-Acrylic acid) nanogel (CSNPs/P(NIPAm-co-AAc)), making significant advancements. The nanogel effectively encapsulated doxorubicin hydrochloride (Dx. HCl), a model drug, within its compartments through electrostatic binding. Comparing nano chitosan (CSNPs) before and after integrating copolymerized P(NIPAm-co-AAc), highlighting an improved and adaptable nanogel structure with responsive behaviors. The intraperitoneal delivery of Dx-loaded nanogel (Dx@N.gel) to Ehrlich ascites carcinoma (Eh)-bearing mice at doses equivalent to 1.5 and 3 mg/kg of Dx per day for 14 days exhibited superiority over the administration of free Dx. Dx@N.gel demonstrated heightened anticancer activity, significantly improving mean survival rates in Eh mice. The nanogel's multifaceted defense mechanism mitigated oxidative stress, inhibited lipid peroxidation, and curbed nitric oxide formation induced by free Dx. It effectively countered hepatic DNA deterioration, normalized elevated liver and cardiac enzyme levels, and ameliorated renal complications. This pH-responsive CSNPs/P(NIPAm-co-AAc) nanogel loaded with Dx represents a paradigm shift in antitumor drug delivery. Its efficacy and ability to minimize side effects, contrasting sharply with those of free Dx, offer a promising future where potent cancer therapies seamlessly align with patient well-being.


Subject(s)
Carcinoma, Ehrlich Tumor , Chitosan , Doxorubicin , Drug Carriers , Nanogels , Polyethyleneimine , Animals , Chitosan/chemistry , Doxorubicin/chemistry , Doxorubicin/pharmacology , Doxorubicin/administration & dosage , Carcinoma, Ehrlich Tumor/drug therapy , Carcinoma, Ehrlich Tumor/pathology , Mice , Drug Carriers/chemistry , Nanogels/chemistry , Drug Liberation , Polyethylene Glycols/chemistry , Drug Delivery Systems , Hydrogen-Ion Concentration , Nanoparticles/chemistry , Oxidative Stress/drug effects
2.
ACS Omega ; 9(9): 10058-10068, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38463317

ABSTRACT

The diagnosis and prognosis of chronic wounds are demanding and require objective assessment. Because of their potential medicinal applications, the syntheses of biopolymeric chitosan (CHN) structure and PVA-based mixed electrospun nanofibers with biomimetic features were thoroughly investigated. This study created different formulas, including a guest molecule and capping agent, using supporting PVA as a vehicle. CHN was used as a biomodifier, and beta-cyclodextrin (ß-CD) as a smoother and more efficiently entraps streptomycin (STP) compared with the silver sheet wound dressing. The relevant analyses showed that the size distribution increased with the incorporation of PVA, CHN, and ß-CD to 120.3, 161.9, and 192.02 nm. The webs boosted particle size and released content stability to 96.4% without compromising the nanofiber structure. Examining the synergistic effects of the PVA/CHN/STP/ß-CD nanoformulation against pathogenic strains of S. aureus, P. aeruginosa, and Aspergillus niger, clean zones were 47 ± 3.4, 45 ± 3.0, and 49 ± 3.7 mm were produced. PVA/CHN/STP/ß-CD formula exhibited a 98.9 ± 0.6% cell viability and wound closure of 100% at 72 h. The results reveal that the PVA/CHN/STP/ß-CD formula is promising for medical applications, especially in wound healing, compared with the silver sheet.

4.
Sci Rep ; 14(1): 7062, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38528000

ABSTRACT

Poly L(+) lactic acid (PLLA) has become crucial in the biomedical industry for various uses. The direct polycondensation method was used to prepare Poly L(+) Lactic Acid (PLLA). Different catalysts, including metal oxides and metal halides, were used to test the polymerization technique. The effect of the amount of catalysts and the type of coupling agent were investigated. The effect of reaction time and polymerization solvents was also studied. PLLA was loaded with isosorbide dinitrate utilizing the solvent evaporation process. The synthesized polymer-drug system was evaluated by different means such as FT-IR, TGA, DSC, XRD, entrapment efficiency (E.E), drug loading (D.L), particle size analysis, and zeta potential determination. Studies on in-vitro release using UV light at 227 nm at various pH levels were conducted, and the kinetics of release and cytotoxicity using the sulforhodamine B (SRB) assay on human skin fibroblast cells were examined.

6.
ACS Omega ; 8(39): 35682-35692, 2023 Oct 03.
Article in English | MEDLINE | ID: mdl-37810675

ABSTRACT

Abundant chitosan was rationally used for the green fabrication of cadmium oxide nanorods (CdO nanorods) owing to its environmentally benign characteristics, bioavailability, low cost, etc. However, the primary unsubstituted amino group of chitosan interacts with the surface of Cd salt at higher temperatures, resulting in CdO nanorod formation. A one-step hydrothermal technique was adopted in the presence of chitosan. Optical, structural, and morphology techniques characterized CdO nanorods. According to X-ray diffraction crystallography, CdO is well crystallized in the face-centered cubic lattice with an Fm-3m (225) space group. The AC@CdO nanoelectrode demonstrated an outstanding gravimetric capacitance of 320 F g-1 at a current density of 0.5 A g-1, nearly three-fold that of ordinary AC electrodes. The AC electrode and the AC@CdO nanoelectrode retain 90 and 93% of their initial specific capacitance after 10,000 galvanostatic charge discharge cycles. The AC@CdO nanoelectrode has a lower equivalent series resistance value than the AC electrode. Moreover, AC@CdO symmetric supercapacitor devices achieve excellent results in terms of specific energy, specific power, and capacitance retention.

7.
Int J Biol Macromol ; 247: 125779, 2023 Aug 30.
Article in English | MEDLINE | ID: mdl-37442506

ABSTRACT

Chitosan (Cs) was subjected to ball milling and subsequently functionalized with Dinitro salicylic acid (Cs-DNS) to enhance the efficacy of oral insulin delivery. The hydrodynamic spherical particle sizes exhibited 33.29 ± 5.08 nm for modified Cs-DNS NPs. Irrespective of insulin entrapment, zeta potential measurements revealed positively charged Cs-DNS NPs (+ 35 ± 3.5 mV). The entrapment performance (EP%) was evaluated in vitro, and insulin release patterns at various pH levels. The EP% for Cs-DNS NPs was 99.3 ± 1.6. Cs- DNS NPs retained a considerable amount of insulin (92 %) in an acidic medium, and significant quantities were released at increasing pH values over time. In vivo investigations, the diabetic rats which taken insulin-incorporated NPs had lower serum glucose levels (SGL) after 3 h to (39.4 ± 0.6 %) for Cs- DNS NPs. For insulin-incorporated Cs- DNS NPs, the bioavailability (BA%) and pharmacological availability (PA%) were 17.5 ± 0.31 % and 8.6 ± 0.8 %, respectively. The assertion above highlights the significance and effectiveness of modified chitosan in promoting insulin delivery, decreasing SGL levels, and guaranteeing safety.


Subject(s)
Chitosan , Diabetes Mellitus, Experimental , Nanoparticles , Rats , Animals , Insulin , Chitosan/therapeutic use , Drug Carriers/therapeutic use , Diabetes Mellitus, Experimental/drug therapy , Microwaves , Administration, Oral , Particle Size
8.
Int J Biol Macromol ; 242(Pt 4): 124936, 2023 Jul 01.
Article in English | MEDLINE | ID: mdl-37236566

ABSTRACT

Reduction of renal function, such as creatinine adsorption is one of the most common and dangerous diseases. Dedicated to this issue, developing high-performance, sustainable, and bio-compatible adsorbing materials is still challenging. Herein, barium alginate (BA) and BA containing few-layer graphene (FLG/BA) beads were synthesized in water from sodium alginate, also acting as bio-surfactant in in-situ exfoliation of graphite to FLG. The physicochemical characteristics of the beads demonstrated an excess of barium chloride used as a cross-linker. The efficiency and sorption capacity (Qe) of creatinine removal increase with processing duration reaching 82.1, 99.5 %, and 68.4, 82.9 mg·g-1 for BA and FLG/BA, respectively. The thermodynamic parameters detect the enthalpy change (ΔH°) of about -24.29 and -36.11 kJ·mol-1 and the entropy change (ΔS°) of around -69.24 and -79.46 J·mol-1 K-1 for BA and FLG/BA, respectively. During the reusability test, the removal efficiency decreases from the optimal first cycle to 69.1 and to 88.3 % in the sixth cycle for BA and FLG/BA, revealing superior stability of FLG/BA. The MD calculations confirm a higher adsorption capacity of FLG/BA composite compared to BA alone, clearly confirming a strong structure-property relation.


Subject(s)
Graphite , Graphite/chemistry , Creatinine , Alginates/chemistry , Thermodynamics , Kidney/physiology , Adsorption
9.
Int J Biol Macromol ; 234: 123620, 2023 Apr 15.
Article in English | MEDLINE | ID: mdl-36773863

ABSTRACT

This study presents the development of an electrochemical supercapacitor with a cadmium selenide nanoparticles (CdSeNPs) electrode utilizing a straightforward and economical method based on kappa-carrageenan (κ-CGN). The structural, morphological, and optical characteristics of CdSeNPs were assessed. Activated carbon (AC) and green-prepared CdSeNPs were easily mixed to achieve excellent electrochemical properties. The nanoelectrode (AC@CdSe) was tested in an aqueous electrolyte of sodium sulfate (Na2SO4) with a concentration of 1 Molar. Specific capacitance (Csp) for the AC electrode and the AC@CdSe electrode at 1 A g-1 was calculated to be 103 and 480 F g-1, respectively. Besides, the symmetric supercapacitor AC@CdSe/AC@CdSe device has a high specific energy of 52 Wh kg-1 and a maximum specific power of 2880 W kg-1, with a specific capacitance of 115.5 F g-1. With a coulombic efficiency of between 82 % and 100 %, the device continues to maintain excellent capacitance after 10.000 cycles.


Subject(s)
Charcoal , Nanoparticles , Carrageenan , Electrolytes
10.
ACS Omega ; 7(27): 23673-23684, 2022 Jul 12.
Article in English | MEDLINE | ID: mdl-35847248

ABSTRACT

The benign preparation of cobalt oxide nanoparticles (Co3O4-NPs) was performed using marine red algae extract (Grateloupia sparsa) as a simple, cost-effective, scalable, and one-pot hydrothermal technique. The nominated extract was employed as an environmental reductant and stabilizing agent. The resultant product showed the typical peak of Co3O4-NPs around 400 nm wavelength as ascertained by UV-vis spectroscopy. Size and morphological techniques combined with X-ray diffraction (XRD) showed the small size of Co3O4-NPs deformed in a spherical shape. The activated carbon (AC) electrode and Co3O4-NP electrode delivered a specific capacitance (C sp) of 125 and 182 F g-1 at 1 A g-1, respectively. The energy density of the AC and AC/Co3O4 electrodes with a power density of 543.44 and 585 W kg-1 was equal to 17.36 and 25.27 Wh kg-1, respectively. The capacitance retention of designed electrodes was 99.2 and 99.5% after 3000 cycles. Additionally, a symmetric AC/Co3O4//AC/Co3O4 supercapacitor device had a specific capacitance (C sp) of 125 F g-1 and a high energy density of 55 Wh kg-1 at a power density of 650 W kg-1. Meanwhile, the symmetric device exhibited superior cyclic stability after 8000 cycles, with a capacitance retention of 93.75%. Overall, the adopted circular criteria, employed to use green technology to avoid noxious chemicals, make the AC/Co3O4 nanocomposite an easily accessible electrode for energy storage applications.

11.
PLoS One ; 17(6): e0266019, 2022.
Article in English | MEDLINE | ID: mdl-35679274

ABSTRACT

BACKGROUND: Disturbed sleep can cause to m health problems such as cognitive impairment, depressed mood, and negative effects on cardiovascular, endocrine, and immune function. This study formulates and optimizes Eszopiclone trilaminate fast dissolving film. METHODS: Prepared Eszopiclone trilaminate fast dissolving film (Eszopiclone TFDF) was characterized by disintegration time, drug release, tensile strength (TS), percentage elongation (EB%), folding endurance, taste masking test, and in vitro dissolution test. The selected formulas were F2 (0.5% xanthan gum, 10% propylene glycol), F4 (3% sodium alginate, 10% propylene glycol) and F6 (1.5% pullulan, 10% propylene glycol) were subjected to in vivo study compared to conventional Lunesta® tablet. RESULTS: The results indicated that disintegration time was in the range of 940 m. Drug release was found to be in the field of 78.51%-99.99%, while TS values and EB% differed from 11.12 to 25.74 (MPa) and 25.38%-36.43%, respectively. The folding endurance went between 200 and 300 times. All formulas exhibited acceptable uniformity content, surface pH, film thickness, and a good taste feeling. CONCLUSION: F4 had the highest Cmax (39.741 ± 6.785-µg/l) and lower Tmax (1.063 hr) among other formulas and conventional tablets. Therefore, FDFs' technology could increase the therapeutic effect of Eszopiclone.


Subject(s)
Sleep Initiation and Maintenance Disorders , Biological Availability , Eszopiclone , Humans , Propylene Glycols , Research Subjects , Sleep Initiation and Maintenance Disorders/drug therapy , Solubility , Tablets/chemistry
12.
Int J Biol Macromol ; 209(Pt B): 2188-2196, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35504421

ABSTRACT

Chitosan-based nanoparticles (chitosan nanoparticles (ChNps), chitosan gold Nps (ChAuNps), and chitosan gold Nps functionalized with poly lactic-co-glycolic acid (PLGA) (ChAuNps/PLGA)) were prepared as nanocarriers for insulin to improve its oral uptake. The emulsion solvent diffusion method was employed to functionalize the Nps with PLGA. TEM, SEM, DLS, and zeta potential were conducted to characterize the Nps. The morphological analysis confirmed the formation of spherical Nps with hydrodynamic particle sizes of 138±23, 16±2.2, and 50±9.3 nm for ChNps, ChAuNps, and ChAuNps/PLGA, respectively. Zeta potential measurements indicated two types of Nps, regardless of insulin entrapment, positively charged, (ChNps (+36 ± 4.2, +31 ± 2.2mv)) and ChAuNps (+37 ± 4.3, +33 ± 2.5mv) and negatively charged (ChAuNps/PLGA (-31 ± 2.7, -26 ± 2.1 mv)). The in vitro studies were assessed by measuring the entrapment efficiencies (EE%) and the release profiles of insulin at different pH values. EE% for ChNps, ChAuNps, and ChAuNps/PLGA were 97 ± 1.5, 98.4 ± 1.9, and 99 ± 1.2%, respectively. At an acidic medium, a significant level of insulin retention was observed (96 ± 0.08%) for ChAuNps/PLGA. While a high amount was released at higher pH values over an extended period of time. In vivo studies, diabetic rats treated with insulin-loaded Nps had reduced blood glucose level (BGL) (38 ± 2.8, 35 ± 6.5, and 27 ± 5.6%) for ChNps ChAuNps and ChAuNps/PLGA, respectively. The pharmacological availability (PA%) and bioavailability (FR%) for insulin-loaded ChAuNps/PLGA were 15.8 ± 0.71% and 7.7 ± 0.93%, respectively. Altogether, emphasize the role of biocompatible Nps and their efficiency in the convenient delivery of insulin, thus lowering the BGL in a safe condition.


Subject(s)
Chitosan , Diabetes Mellitus, Experimental , Metal Nanoparticles , Nanoparticles , Animals , Chitosan/chemistry , Diabetes Mellitus, Experimental/drug therapy , Drug Carriers/chemistry , Glycols , Gold/therapeutic use , Insulin/chemistry , Lactic Acid/chemistry , Nanoparticles/chemistry , Particle Size , Polyglycolic Acid/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer , Rats
13.
Int J Biol Macromol ; 204: 161-168, 2022 Apr 15.
Article in English | MEDLINE | ID: mdl-35074332

ABSTRACT

It has been more than one year since the first case of the coronaviruses was infected by COVID-19 in China. The world witnessed three waves of the corona virus till now, and more upcoming is expected, whereas several challenges are presented. Empirical data displayed that the features of the virus effects do vary between the three periods. The severity of the disease, differences in symptoms, attitudes of the people have been reported, although the comparative characteristics of the three waves still keep essentially indefinite. In contrast, the sense of danger toward the cries gradually decreases in most countries. This may be due to some factors, including the approved vaccines, introducing alternative plans from politicians to control and deal with the epidemic, and decreasing the mortality rates. However, the alarm voice started to rise again with the appearance of new variant strains with several mutations in the virus. Several more questions began to be asked without sufficient answers. Mutations in COVID-19 have introduced an extreme challenge in preventing and treating SARS-COV-2. The essential feature for mutations is producing new variants known by high tensmibility, disturbing the viral fitness, and enhancing the virus replication. One of the variants that has emerged recently is the Delta variant (B.1.617.2), which was firstly detected in India. In November 2021, a more ferocious mutant appeared in South Africa, also called omicron (B.1.1.529). These mutants grabbed world attention because of their higher transmissibility than the progenitor variants and spread rapidly. Several information about the virus are still confusing and remains secret. There are eight approved vaccines in the market; however, the investigation race about their effect against reinfection and their role against the new variants is still under investigation. Furthermore, this is the first time vaccinating against COVID-19, so the question remains: Will we need an annual dose of the corona vaccines, and the side effects don't been observed till now?


Subject(s)
COVID-19/epidemiology , SARS-CoV-2/genetics , Vaccination/trends , COVID-19 Vaccines/genetics , Humans , Pandemics , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Vaccination Coverage/trends
14.
Biomass Convers Biorefin ; : 1-15, 2022 Jan 17.
Article in English | MEDLINE | ID: mdl-35070632

ABSTRACT

It is well known that biogenic synthesis, as compared to other processes, has proven to be highly effective in the fabrication of silver nanoparticles (AgNPs). Thus, our current study focused on synthesizing AgNPs using coffee waste extract (CWE). CWE contains many compounds identified by HPLC, which reduce, cap, and stabilize AgNPs in its solution. The as-synthesized AgNPs were produced with a monodispersed small size around 20 nm and exhibited in-plane dipole plasmon resonances of hexagonal nanoplates. AgNPs were characterized by both physical and spectroscopic methods, which confirmed their nanoscale dimensions with a hexagonal shape. The as-prepared AgNPs (12 mg) enabled the photodegradation of phenol compounds (20 mL) with a removal efficiency of ~ 94.6% in a short time in the presence of citric acid. Additionally, the second promising application of AgNPs was the tendency to remove the hazard 2,4 dinitroaniline (2,4 DNA) with a percent more than 97% while using only 7 mg of AgNPs. Moreover, the green synthesized AgNPs are superior in inhibiting bacterial growth and killing most infected microbes such as B. subtilis, P. aeruginosa, S. aureus, and E. coli. The electrochemical characteristics of the AgNPs were evaluated using a three-electrode system. The calculated specific capacitance was 280 F g-1 at 0.56 A g-1. Furthermore, after 1000 cycles at 2.2 A g-1, the AgNPs electrode demonstrates an excellent cycling stability behavior with 94.8% capacitance retention. Based on the previous promising results, it can be concluded that CWE is an environmentally benign extract to prepare AgNPs with low cost, saving and easily used for many great domains in photocatalytic, phenol compound removals, and production of functional nanodevices.

15.
ACS Omega ; 6(36): 23090-23099, 2021 Sep 14.
Article in English | MEDLINE | ID: mdl-34549110

ABSTRACT

In this work, we produced high yield quantized nitrogen-doped graphene nanodiscs from waste tires via a one-step process under high pressure and temperature using a homemade stainless steel reactor without using any chemical additives. Reaction temperature played a vital role in the preparation process. By increasing the temperature to a level between 600 and 1100 °C, the carbon atoms rearranged themselves to build a mixed graphene structure of nanodiscs and quantum dots. The obtained graphene exhibits excellent capacitance and long life cycle stability as an electrode in supercapacitor devices. The specific capacitance rose to 161.24 F/g with a high power density of 733.3 W/kg, and the energy density reached 27.1 Wh/kg. The finding of this work is not only to provide a solution to get rid of hazardous materials but also to give awareness of turning these hazardous materials into a cost-effective and economical nanomaterial; in another, this approach sheds light on the promising power uses of waste.

16.
Ann Biomed Eng ; 49(9): 2006-2029, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34378121

ABSTRACT

The most common forms of tissue impairment are fracture bones and significant bone disorders caused by multiple traumas or normal aging. Surgical care sometimes necessitates the placement of a temporary or permanent prosthesis, which continues to be a challenge for orthopedic surgeons, including those with large bone defects. Electrospun scaffolds made from natural and synthetic nanofiber-based polymers are studied as natural extracellular matrix (ECM)-like scaffolds for tissue engineering. Besides, nanostructured materials have properties and functions depending on the scale of natural materials such as hydroxyapatite (HAP), ranging from 1 to 100 nm, which activity was proficient upon enrolled in nanofiber mats. The use of nanofibers in combination with nano-HAP has increased the scaffold's ability to replicate the construction of natural bone tissue that is the aim of the present text. In bone engineering, nanofiber substrates facilitate cell adhesion, proliferation, and differentiation, while HAP induces cells to secrete ECM for bone mineralization and development. This review aims to draw the reader's attention to the critical issues with synthetic and natural polymers containing HAP in bone tissue engineering; co-substituted hydroxyapatite has also been mentioned.


Subject(s)
Bone and Bones , Durapatite , Nanofibers , Polymers , Tissue Engineering/methods , Animals , Bone Diseases/therapy , Bone and Bones/anatomy & histology , Durapatite/chemistry , Humans , Nanofibers/chemistry , Polymers/chemistry
17.
Spectrochim Acta A Mol Biomol Spectrosc ; 261: 120008, 2021 Nov 15.
Article in English | MEDLINE | ID: mdl-34087770

ABSTRACT

Self-assembly of Sofosbuvir drug (SOF) anti-hepatitis C virus (HCV) with bio-polymeric nanoparticles such as chitosan nanoparticles (Cs NPs) and polyvinyl alcohol nanoparticles (PVA NPs), the novel composites have been characterized successfully by different analysis such as Energy-dispersive X-ray spectroscopy (EDX), Scanning electron microscopy (SEM), UV-Visible spectrophotometer (UV-Vis) and Fourier Transmittance Infrared (FT-IR). The improvement of the Sofosbuvir effect as a result of loading drug on the bio-polymer NPs surface has been detected by the UV-Vis, and fluorescence spectroscopy techniques. The improvement of SOF efficiency was revealed via studying the drug release of SOF from biopolymers NPs surface at pH 7.4, UV-Vis spectra used for the releasing process. The binding constant (Kb) value was reported at 0.000055 and 0.3613 min-1 for Cs and PVA NPs respectively. Also, the value of KSV was documented at 0.0014 and 7.16 min-1 for Cs@SOF and PVA@SOF hybrid nanocomposite. The incorporation rate (k) of SOF on the surface of biopolymer nano molecules was calculated to be 0.00812 and 0.0165 min-1 for Cs and PVA NPs, respectively. Besides the observed value of (n) was close to the unit 0.74 and 0.86 for Cs and PVA NPs, respectively. The SOF released from Cs NPs surface was documented at 0.09 mg after 24 h, while PVA NPs reported at 0.7 mg at the same time and the release efficiency is 56.5 and 73% for Cs@SOF and PVP@SOF, respectively. From the results, we suggest Cs/SOF and PVA/SOF hybrid nanocomposites have spectroscopic results that make them promising candidate drugs, but need to the clinical trials.


Subject(s)
Chitosan , Nanoparticles , Pharmaceutical Preparations , Drug Liberation , Polymers , Sofosbuvir , Spectroscopy, Fourier Transform Infrared
18.
ACS Omega ; 6(20): 13077-13086, 2021 May 25.
Article in English | MEDLINE | ID: mdl-34056457

ABSTRACT

In this article, we investigate the application of polythiophene (PT), polythiophene with embedded gold nanoparticles (PT-Au), and polythiophene with embedded palladium nanoparticles (PT-Pd) via the spin coating technique on the rear contact of single-crystalline silicon solar cells. Several layers of coating (up to four layers) were applied, followed by a simple heat treatment at 70 °C for 30 min. The morphology, particles distribution in the polymer, and crystal structure of the colloid PT, PT-Au, and PT-Pd were characterized by transmission electron microscopy (TEM). Optical characteristics of the polymer and nanoparticles embedded in the polymers exhibited high absorption in the near-UV region, and a plasmonic peak at around 580 nm is observed. The calculated energy gap ranged from 2.65 eV (PT-Pd 5%) to 2.9 eV (PT) and 3.05 eV (PT-Au 5%). Scanning electron microscopy (SEM) images of the successive layers show an increase in the density and thickness of the PT particles with increasing number of coating layers, up to 12 µm for four layers of PT. Devices were characterized under dark conditions exhibiting variations in the ideality factor and series and shunt resistances with different coating layers. The silicon solar cells were characterized by measuring quantum efficiency, photoconversion efficiency (PCE), fill factor, and series and shunt resistances before and after coating. The coating was found to reduce the series resistance and to increase the efficiency of the cell by up to 7.25% for the PT-Au5% layers.

19.
Int J Pharm ; 593: 120143, 2021 Jan 25.
Article in English | MEDLINE | ID: mdl-33279712

ABSTRACT

The development of a scaffold matrix that can inhibit bacterial infection and promote wound healing simultaneously is an essential demand to improve the health care system. Hydroxyapatite (HAP) doped with different concentrations of silver ions (Ag+) were incorporated into electrospun nanofibrous scaffolds of polycaprolactone (PCL) using the electrospinning technique. The formed phase was identified using XRD, while the morphological and roughness behavior were investigated using FESEM. It was shown that scaffolds were configured in randomly distributed nanofibers with diameters around of 0.19-0.40, 0.31-0.54, 1.36, 0.122-0.429 µm for 0.0Ag-HAP@PCL, 0.2Ag-HAP@PCL, 0.6Ag-HAP@PCL, and 0.8Ag-HAP@PCL, respectively. Moreover, the maximum roughness peak height increased significantly from 179 to 284 nm, with the lowest and highest contributions of Ag. The mechanical properties were examined and displayed that the tensile strength increased from 3.11 ± 0.21 MPa to its highest value at 3.57 ± 0.31 MPa for 0.4Ag-HAP@PCL. On the other hand, the cell viability also was enhanced with the addition of Ag and improved from 97.1 ± 4.6% to be around 102.3 ± 3.1% at the highest contribution of Ag. The antibacterial activity was determined, and the highest imbibition zones were achieved at the highest Ag dopant to be 12.5 ± 1.1 mm and 11.4 ± 1.5 mm against E. coli and S. aureus. The in vitro cell proliferation was observed through human fibroblasts cell lone (HFB4) and illustrated that cells were able to grow and spread not only on the fibers' surface but also, they were spreading and adhered through the deep pores.


Subject(s)
Durapatite , Nanofibers , Anti-Bacterial Agents/pharmacology , Bandages , Cell Adhesion , Escherichia coli , Humans , Polyesters , Silver , Staphylococcus aureus , Tissue Scaffolds
20.
Int J Biol Macromol ; 167: 1176-1197, 2021 Jan 15.
Article in English | MEDLINE | ID: mdl-33197477

ABSTRACT

Recent advancements in the synthesis, properties, and applications of chitosan as the second after cellulose available biopolymer in nature were discussed in this review. A general overview of processing and production procedures from A to Z was highlighted. Chitosan exists in three polymorphic forms which differ in degree of crystallinity (α, ß, and γ). Thus, the degree of deacetylation, crystallinity, surface area, and molecular mass significantly affect most applications. Otherwise, the synthesis of chitosan nanofibers is suffering from many drawbacks that were recently treated by co-electrospun with other polymers such as polyvinyl alcohol (PVA), polyethylene oxide (PEO), and polycaprolactone (PCL). Ultimately, this review focuses on the area of new trend utilization of chitosan nanoparticles as nanospheres and nanocapsules, in cartilage and bone regenerative medicine. Owing to its biocompatibility, bioavailability, biodegradability, and costless synthesis, chitosan is a promising biopolymeric structure for water remediation, drug delivery, antimicrobials, and tissue engineering.


Subject(s)
Bioprinting/methods , Chitosan/chemistry , Chitosan/pharmacology , Drug Delivery Systems/methods , Nanocapsules/chemistry , Nanofibers/chemistry , Nanoparticles/chemistry , Tissue Engineering/methods , Anti-Infective Agents/pharmacology , Biocompatible Materials/chemistry , Nanocapsules/ultrastructure , Nanoparticles/ultrastructure , Solubility , Tissue Scaffolds/chemistry
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