Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 65
Filtrar
1.
Artigo em Inglês | MEDLINE | ID: mdl-38757165

RESUMO

Graphene oxide, a derivative of graphene, has recently emerged as a promising nanomaterial in the biomedical field due to its unique properties. Its potential as a nanocarrier in the treatment of Alzheimer's disease represents a significant advancement. This abstract outlines a study focused on utilizing graphene oxide to reduce the toxicity of Alzheimer's proteins, marking a revolutionary approach in treatment strategies. The pathological features of Alzheimer's disease, primarily focusing on the accumulation and toxicity of amyloid-beta proteins, have been described in this review. These proteins are known to form plaques in the brain, leading to neuronal damage and the progression of Alzheimer's disease. The current therapeutic strategies and their limitations are briefly reviewed, highlighting the need for innovative approaches. Graphene oxide, with its high surface area, biocompatibility, and ability to cross the blood-brain barrier, is introduced as a novel nanocarrier. The methodology involves functionalizing graphene oxide sheets with specific ligands that target amyloid-beta proteins. This functionalization facilitates the binding and removal of these toxic proteins from the brain, potentially alleviating the symptoms of Alzheimer's disease. Preliminary findings indicate a significant reduction in amyloid-beta toxicity in neuronal cell cultures treated with graphene oxide nanocarriers. The study also explores the biocompatibility and safety profile of graphene oxide in biological systems, ensuring its suitability for clinical applications. It calls for further research and clinical trials to fully understand and harness the benefits of this nanotechnology, paving the way for a new era in neurodegenerative disease therapy.

2.
Protein Pept Lett ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38629378

RESUMO

The landscape of cancer therapy has witnessed a paradigm shift with the emergence of innovative delivery systems, and Guanidinium-based Peptide Dendrimers have emerged as a vanguard in this transformative journey. With their unique molecular architecture and intrinsic biocompatibility, these dendrimers offer a promising avenue for the targeted delivery of therapeutic cargo in cancer treatment. This comprehensive review delves into the intricate world of Guanidinium- based Peptide Dendrimers, unraveling their structural intricacies, mechanisms of action, and advancements that have propelled them from laboratory curiosities to potential clinical champions. Exploiting the potent properties of guanidinium, these dendrimers exhibit unparalleled precision in encapsulating and transporting diverse cargo molecules, ranging from conventional chemotherapeutics to cutting-edge nucleic acids. The review navigates the depths of their design principles, investigating their prowess in traversing the complex terrain of cellular barriers for optimal cargo delivery. Moreover, it delves into emerging trends, such as personalized therapeutic approaches, multimodal imaging, and bioinformatics-driven design, highlighting their potential to redefine the future of cancer therapy. Crucially, the review addresses the pivotal concerns of biocompatibility and safety, examining cytotoxicity profiles, immune responses, and in vivo studies. It underscores the importance of aligning scientific marvels with the stringent demands of clinical applications. Through each section, the narrative underscores the promises and possibilities that Guanidinium-based Peptide Dendrimers hold and how they can potentially reshape the landscape of precision cancer therapy.

3.
Drug Chem Toxicol ; : 1-13, 2024 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-38311820

RESUMO

The lack of toxicity data for DHA-rich oil from Schizochytrium sp. (Strain ATCC-20889) leads to its exclusion from the Qualified Presumption of Safety list. Therefore, present study addresses toxicity evaluation of DHA-rich microalgae oil using ex-vivo (cytotoxicity assay) and in-vivo methods (acute (OECD 423 guidelines), sub-chronic (OECD 452 guidelines), and genotoxicity assay). The ex-vivo results showed >90% cell viability of Caco-2 cells after 48 h of treatment (200 µg/mL of DHA). Additionally, the in-vivo acute toxicity study found that microalgae oil was nontoxic and classified under category 5 molecule according to OECD 423 guidelines with a highest degree of safety at 2000 mg/kg b.w. The in-vivo sub-chronic study revealed no significant mortality and changes in feed intake, body weight, haematological, biochemical, neurological, and urine parameters after repeated 180-days administration of DHA-rich microalgae oil at 250 mg/kg, 500 mg/kg, and 1000 mg/kg. Moreover, histopathology evaluation, comet assay, chromosomal aberration, and micronuclei assay also confirmed the nontoxic behavior of DHA-rich oil. Thus, the results from the ex-vivo and in-vivo studies indicate that DHA-rich oil from Schizochytrium sp. (Strain ATCC-20889) is safe for use as a novel food, and can be included in infants, adults, pregnant women, and children formula.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38291224

RESUMO

Aceclofenac (ACE) is a drug that was precisely devised to circumvent the shortcomings associated with diclofenac. However, ACE too corresponds to nonsteroidal anti-inflammatory drug (NSAID)-related adverse effects, but with a lower amplitude. The present investigation seeks to develop liposomes loaded with ACE adopting a central composite design (CCD) and formulate a chitosan-based hydrogel for synergistic anti-inflammatory efficacy and improved ACE dermal administration. On the basis of preliminary vesicle size, Poly Dispersity Index (PDI), and drug entrapment, the composition of lipid, cholesterol, and vitamin E TPGS were chosen as independent variables. The formulation composition met the specifications for an optimum liposomal formulation, with total lipid concentration (13.5% w/w), cholesterol concentration (10% w/w), and surfactant concentration (2% w/w). With particle size and PDI of 174.22 ± 5.46 nm and 0.285 ± 0.01 respectively, the optimised formulation achieved an entrapment effectiveness of 92.08 ± 3.56%. Based on the CCD design, the optimised formulation Acec-Lipo opt was chosen and was subsequently transformed to a chitosan-based gel formulation for in vitro drug release, penetration through the skin, in vivo analgesic therapeutic activity, and skin irritation testing. % age oedema inhibition was found to be greatest with the Acec-Lipo opt gel formulation, followed by Acec gel. These results reinforce the notion that the inclusion of chitosan resulted in a synergistic effect despite the same strength of the drug. The findings suggested that Acec-Lipo incorporated in chitosan gel for skin targeting might be an effective formulation for topical ACE administration in clinical subjects.

5.
Recent Pat Nanotechnol ; 18(2): 190-206, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37005511

RESUMO

The current work aims to provide a complete sojourn on gastro-retentive drug delivery system (GRDDS) along with formulation methods, polymer selection, and in vitro/ in vivo challenges with finished dosage forms. Ideally, a biopharmaceutical-hindered drug has a rapid clearance and erratic bioavailability due to its low aqueous solubility and permeability. Additionally, it also suffers from high first-pass metabolism and pre-systemic gut wall clearance. Gastro-retentive drug delivery systems have become an emerging technology where newer methodologies and scientific approaches have been used to provide the controlled release of drugs and provide a protective mechanism in the stomach. By the virtue of utilizing GRDDS as a dosage form, these formulations increase Gastroretention time (GRT) which prolongs the controlled release of the drug in the dosage form. GRDDS contribute to increased drug bioavailability and targeting at a site of action, which enhances therapeutic action and offers significant patient compliance. Furthermore, the present work also highlighted the critical role of polymers in favoring drug retention across GIT with the mechanism of gastro-retention and recommended concentration ranges. The emerging technology is also highlighted by the approved drug products and patented formulations in the recent decade which is depicted in a justified manner. GRDDS formulations have demonstrated clinical efficacy, which is supported by a compilation of patents for cutting-edge innovations in dosage forms that can be held in the stomach for an extended period of time.


Assuntos
Sistemas de Liberação de Medicamentos , Patentes como Assunto , Humanos , Preparações de Ação Retardada , Estômago , Polímeros
6.
AAPS PharmSciTech ; 24(8): 220, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37914839

RESUMO

Psoriasis is an auto-immune condition with high keratinocyte hyperproliferation due to lower p53 and p22 levels. Tacrolimus, an immune suppressor, is considered one of the most effective drugs in suppressing psoriasis. Systematic administration of tacrolimus often leads to challenging side effects, namely increased infection risk, renal toxicity, neurological symptoms such as tremors and headaches, gastrointestinal disturbances, hypertension, skin-related problems, etc. To address this, a nanocarrier-based formulation of tacrolimus along with inclusion of hyaluronic acid was developed. The optimization and formulation of ethosomes via the ethanol injection technique were done based on the Box-Behnken experimental design. The results revealed hyaluronic acid-based tacrolimus ethosomes (HA-TAC-ETH) had nanometric vesicle size (315.7 ± 2.2 nm), polydispersity index (PDI) (0.472 ± 0.07), and high entrapment efficiency (88.3 ± 2.52%). The findings of drug release and skin permeation showed sustained drug release with increased dermal flux and enhancement ratio. The effectiveness of HA-TAC-ETH was confirmed in an imiquimod (5%)-prompted psoriasis model. The skin irritation score and Psoriasis Area and Severity Index (PASI) score indicated that HA-TAC-ETH gel has validated a decline in the entire factors (erythema, edema, and thickness) in the imiquimod-induced psoriasis model in contrast with TAC-ETH gel and TAC ointment. The fabricated HA-TAC-ETH opt gel proved to be safe and effective in in vivo studies and could be employed to treat psoriasis further.


Assuntos
Psoríase , Tacrolimo , Humanos , Tacrolimo/uso terapêutico , Ácido Hialurônico/farmacologia , Administração Cutânea , Imiquimode , Psoríase/tratamento farmacológico , Pele
7.
J Orthop Case Rep ; 13(10): 115-120, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37885646

RESUMO

Introduction: Cervical Pott's constitutes about 10% of all Pott's spine cases. In tuberculous spondylitis, initially there occurs destruction of vertebral bodies and further progression may result in adjacent abscesses, leading to cord compression. Objective is to excise the diseased focus and to provide spinal stability. Case Report: We are presenting 3 rare cases of cervical Pott's spine with epidural collection at multiple levels in the cervical region without significant vertebral body destruction that were followed up for a period of 1 year postoperatively. Patients underwent single-level corpectomy and decompression from anterior aspect. In all three cases, we were able to decompress the cord and remove all the collections and also achieved spinal stabilization. Patients had a gradual and complete recovery of motor power within 6 months to 1 year after surgery. Conclusion: Technique used allows accurate visual assessment of the extent of the disease and allows complete decompression of the cord at multiple levels in cervical spine without causing much instability.

8.
Proc Natl Acad Sci U S A ; 120(39): e2303455120, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37722054

RESUMO

Cows produce antibodies with a disulfide-bonded antigen-binding domain embedded within ultralong heavy chain third complementarity determining regions. This "knob" domain is analogous to natural cysteine-rich peptides such as knottins in that it is small and stable but can accommodate diverse loops and disulfide bonding patterns. We immunized cattle with SARS-CoV-2 spike and found ultralong CDR H3 antibodies that could neutralize several viral variants at picomolar IC50 potencies in vitro and could protect from disease in vivo. The independent CDR H3 peptide knobs were expressed and maintained the properties of the parent antibodies. The knob interaction with SARS-CoV-2 spike was revealed by electron microscopy, X-ray crystallography, NMR spectroscopy, and mass spectrometry and established ultralong CDR H3-derived knobs as the smallest known recombinant independent antigen-binding fragment. Unlike other vertebrate antibody fragments, these knobs are not reliant on the immunoglobulin domain and have potential as a new class of therapeutics.


Assuntos
COVID-19 , SARS-CoV-2 , Feminino , Animais , Bovinos , Anticorpos , Fragmentos Fab das Imunoglobulinas/genética , Dissulfetos
9.
Ther Deliv ; 14(7): 459-472, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37559461

RESUMO

The currently available formulations provided non-targeted treatment of colon cancer, the deadliest cancer variant. Due to biopharmaceutical hindrances, the majority of the drugs are unable to reach the target site. Polylactic-co-glycolic acid (PLGA) is one of the versatile polymers in cancer treatment, diagnostics and theranostics. The unique mechanism of surface modifications in PLGA properties in colon cancer has been a keen interest to be used in different nanoparticles for improving biopharmaceutical attributes. The ongoing use of these smart nano-carriers has allowed targeted delivery of several active components on a wide scale. The main goal of this review is to compile information on PLGA-based nanocarriers which possess several desirable properties for drug delivery applications, including biocompatibility, biodegradability and tunable drug-release kinetics.


Assuntos
Neoplasias do Colo , Nanopartículas , Humanos , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Polímeros , Glicóis , Sistemas de Liberação de Medicamentos , Nanotecnologia , Neoplasias do Colo/tratamento farmacológico , Portadores de Fármacos
10.
Cureus ; 15(7): e41822, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37575715

RESUMO

Odontogenic keratocysts (OKC) are aggressive cysts with a high recurrence potential. Treating them with surgical enucleation procedures alone is associated with high recurrence rates; therefore, additional or supportive treatment approaches, such as peripheral osteotomy, cryotherapy, and chemical solutions, are warranted. The objective of the present review was to evaluate the existing literature on the efficacy of chemical approaches, such as Carnoy's solution (CS), in preventing recurrence after the enucleation of OKC. An electronic search was conducted on PubMed, Scopus, and Google Scholar databases to find articles published from January 2010 to December 2022 by using the Medical Subject Headings (MeSH) terms "Odontogenic Keratocyst" "Carnoy's Solution," "Treatment," and "Enucleation." Articles published in the English language were selected for the study. The PICOS criteria (population: patients with non-syndromic OKC with histopathological diagnosis and a minimum follow-up of six months; intervention and comparison: enucleation followed by adjunctive chemical therapy and standard procedure; outcome: recurrence rates; study design: retrospective and prospective studies, randomized controlled trials, and case series involving at least 10 cases of OKC) were employed. Studies involving syndromic (nevoid basal cell carcinoma) cases were excluded from the search. Seventeen studies fulfilled the inclusion criteria and the majority of them were retrospective studies, with a few case series. OKC was found more frequently in the mandible, with a recurrence rate of 11%, when treated with CS following enucleation after four years of follow-up. Modified Carnoy's solution (MC) was used in two studies. The mean follow-up period was 44 months. Based on our findings, adjuvant therapy using a chemical approach following enucleation is a more effective and beneficial modality for the treatment of OKC.

11.
Artigo em Inglês | MEDLINE | ID: mdl-37497703

RESUMO

Fungal infections are becoming one of the most common diseases in recent years, especially when it comes about dealing skin infections. Different drugs are available commercially with antifungal activity for topical application and are effective for treatment of mild to moderate fungal infections. However they lack dermal bioavailability due to their poor penetrability, and less retention at the site thereby resulting in poor efficacy. The remaining systemic treatment options available so far may cause adverse drug effects and many other complications. In recent years nano carrier based formulations promised to overcome the limitations of the conventional topical dosage forms. Lipid based nano carriers and their importance for potential use in delivery of antifungal agents for the treatment of superficial fungal infections have been well discussed in this review article. It comprises of different nano lipid systems involved in treatment of topical fungal infections, effect of different polymers on their size, stability, and their mechanistic action behind skin penetration and dermal retention of drug into deeper epidermal layers is also highlighted to depict recent efforts of researchers in this context. Further, the addressing of the disease by novel drug delivery systems for the efficacious treatment, status of clinical trials, novel commercial formulations available for use in dermal drug delivery and patents claimed/granted in the respective field have been discussed in detail.

12.
Neurodiagn J ; 63(3): 205-214, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37506256

RESUMO

Background: The intensive physical regimen followed by throwers and archers can impose stress on the elbow and hand in particular positions, which may increase the risk of developing peripheral nerve disorders and symptoms like pain and numbness. Purpose: The purpose of the study is to investigate the effect of forearm and elbow joint positions on ulnar nerve conduction velocity in throwers, archers, and non-athletes. Method: Total 34 subjects both males and females were included with body mass index (BMI) between 18.5 and 24.9 kg/m2. Nerve conduction study (NeuroStim NS2 EMG/NCV/EP System) was used for measuring ulnar nerve conduction velocity (NCV) across elbow joint at different angles (0° elbow extension, 45°, 90°, and 120° elbow flexion) with different forearm positions. Result: Repeated Measure Analysis of Variance (RMANOVA) revealed that there was a statistically significant difference in mean values of ulnar NCV at different angles, forearm positions & groups (p < .05). Conclusion: The forearm and elbow positions can have a significant impact on ulnar NCV, especially in athletes who perform repetitive upper limb motions. Results showed that the archers had significantly slower NCV than throwers and non-athletes at 90° of elbow flexion and forearm pronation.


Assuntos
Articulação do Cotovelo , Antebraço , Masculino , Feminino , Humanos , Antebraço/fisiologia , Nervo Ulnar , Condução Nervosa/fisiologia , Extremidade Superior
13.
Artigo em Inglês | MEDLINE | ID: mdl-37264655

RESUMO

Objectives An autoimmune-mediated dermatological ailment featuring recurrent episodes is acknowledged as psoriasis. Around the world, 2-3% of people suffer from this autoimmune skin condition. The primary goal of the current review is to analyse and determine the effectiveness of conventional and emerging nano technological strategies to alleviate psoriasis and discuss future perspectives. Evidence acquisition A thorough search of numerous electronic databases, including Science Direct, Scopus, Google Scholar, Clinical Trials, Google Patents, Research Gate, and PubMed, yielded all the data used in this review paper about the management of psoriasis via various anti-psoriatic agent and nanotechnology approaches. Keywords such as topical, liposomes, niosomes, micro needles, clinical trials, patents, pathogenesis, biosimilars, cytokines, and other pertinent words were investigated. Results Nano technological approaches are gaining prominence since they enable targeted delivery, rapid onset of action with limited systemic exposure. Researchers have investigated innovative, alternative therapeutic approaches that are both secure and efficient for treating psoriatic conditions. Further, the potential role of numerous psoriatic conventional therapies has been explored. The patents granted or in process to address psoriasis via topical route have been well explored. Modern nanotechnology has made it possible for pharmaceuticals to be delivered with improved physical, chemical, pharmacokinetic, and pharmacodynamic qualities. Despite extensive research complete cure for psoriasis is hampered. Conclusion Relying on the extensive literature review, it can be inferred that nanoparticles based novel delivery strategies have the possibility of enhancing the pharmacological activity and eliminating or resolving problems associated with this ailment. The different drug delivery systems available for the treatment of psoriasis along with the clinical trials in different stages, patents in process and granted, the commercialized status of therapeutic molecules, and the future of research in this area have been thoroughly reviewed.

14.
Cureus ; 15(4): e38164, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37252526

RESUMO

Subdural hemorrhage (SDH) is a common neurological disease. In past, SDHs were managed either conservatively (non-surgically) or with surgical evacuation (burr hole versus craniotomy) depending on the severity. Surgical evacuation has major challenges including high recurrence rate, stoppage and reversal of antiplatelet or anticoagulation agents, risk of general anesthesia and surgery in elderly patients with multiple comorbidities. Given the above challenges, embolization of the distal branches of the middle meningeal artery (MMA) has recently emerged as an excellent alternate to surgical evacuation or conservative management. To the best of our knowledge, there is no literature on the embolization of the deep temporal artery (DTA) for subacute-chronic SDH. We report the first case of recurrent subdural hematoma post MMA embolization that was successfully treated with embolization of DTA.

15.
Curr Drug Deliv ; 2023 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-37157192

RESUMO

Atopic dermatitis (AD), commonly known as Eczema, is a non-communicable skin condition that tends to become chronic. The deteriorating immunological abnormalities are marked by mild to severe erythema, severe itching, and recurrent eczematous lesions. Different pharmacological approaches are used to treat AD. The problem with commercial topical preparations lies in the limitation of skin atrophy, systemic side effects, and burning sensation that decreases patient compliance. The carrier-based system promises to eliminate these shortcomings; thus, a novel approach to treating AD is required. Liposomes, microemulsions, solid lipid nanoparticles (SLNs), nanoemulsions, etc., have been developed recently to address this ailment. Despite extensive research in the development method and various techniques, it has been challenging to demonstrate the commercial feasibility of these carrier-based systems, which illustrates a gap among the different research areas. Further, different soft wares and other tools have proliferated among biochemists as part of a cooperative approach to drug discovery. It is crucial in designing, developing, and analyzing processes in the pharmaceutical industry and is widely used to reduce costs, accelerate the development of biologically innovative active ingredients, and shorten the development time. This review sheds light on the compilation of extensive efforts to combat this disease, the product development processes, commercial products along with patents in this regard, numerous options for each step of computer-aided drug design, including in silico pharmacokinetics, pharmacodynamics, and toxicity screening or predictions that are important in finding the drug-like compounds.

16.
Cureus ; 15(4): e37213, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37159773

RESUMO

The incidence of coil dislocation during an endovascular embolization of intracranial aneurysm is low but it can lead to serious thrombo-embolic complications. Therefore, coil displacement/migration often requires either retrieval or fixation of the errant coil with a stent. There are no standard recommended methods of coil retrieval. We present a series of three cases in which off-label application of a stent retriever allowed successful retrieval of herniated coils.

17.
Cureus ; 15(3): e36640, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37101994

RESUMO

Congenital absence of the internal carotid artery (ICA) is an extremely rare entity that occurs due to insult during the embryonic development of the ICA. Various intracranial collateral pathways develop to compensate for the ICA agenesis. Patients can present with aneurysmal subarachnoid hemorrhage, stroke-like symptoms, or other neurological symptoms due to compression of brain structures from enlarged collateral pathways/aneurysms. We present two cases of ICA agenesis along with an extensive review of the literature. A 67-year-old man presented with fluctuating right-sided hemiparesis and aphasia, found to have left ICA agenesis. The left middle cerebral artery (MCA) is supplied by the basilar artery through the well-developed posterior communicating artery (PCOM). Left ophthalmic artery coming from the proximal left MCA. A 44-year-old woman presented with severe headaches, found to have right ICA agenesis with bilateral MCAs and anterior cerebral arteries (ACA) supplied by left ICA. A 17-mm anterior communicating artery (ACOM) aneurysm was discovered.

18.
Assay Drug Dev Technol ; 21(4): 137-156, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37083490

RESUMO

Continuous drug delivery modification is the scientific approach and is a basic need for the efficient therapeutic efficacy of active drug molecules. Polymer-drug conjugates have long been a hallmark of the drug delivery sector, with various conjugates on the market or in clinical trials. Improved drug solubilization, extended blood circulation, decreased immunogenicity, controlled release behavior, and increased safety are the advantages of conjugating drugs to the polymeric carrier like polyethylene glycol (PEG). Polymer therapies have evolved over the last decade, resulting in polymer-drug conjugates with diverse topologies and chemical properties. Traditional nondegradable polymeric carriers like PEG and hydroxy propyl methacrylate have been clinically employed to fabricate polymer-drug conjugates. Still, functionalized polymer-drug conjugates are increasingly being used to increase localized drug delivery and ease of removal. Researchers have developed multifunctional carriers that can "see and treat" patients using medicinal and diagnostic chemicals. This review focused on the various conjugation approaches for attaching the doxorubicin to different polymers to achieve enhanced therapeutic efficacy, that is, increased bioavailability and reduced adverse effects.


Assuntos
Antineoplásicos , Doxorrubicina , Humanos , Doxorrubicina/efeitos adversos , Doxorrubicina/química , Polímeros/química , Polietilenoglicóis/química , Sistemas de Liberação de Medicamentos , Preparações Farmacêuticas , Antineoplásicos/química
19.
Langmuir ; 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36631941

RESUMO

Epoxies, their derivatives, and composites, due to superior specific strength, are preferred for many potential applications in the field of automobiles, aircraft, bonding of structures, protective coatings, water filtration, etc. As structural members in automobiles and aircraft, the epoxy-based components are exposed to various static/dynamic mechanical loading conditions during their service life. The interfacial interactions, between the matrix and reinforcement, greatly affect the final properties of the composites. The present study demonstrates that the solvent used for the preparation of the composite can also contribute toward interfacial interactions. Present research systematically finds out a suitable solvent (acetone) and reinforcement type [multi-walled carbon nanotube (CNT)] for epoxy [bisphenol-A (BPA)] nanocomposites. Dynamic and static strengths of the as-prepared epoxy-CNT nanocomposites were carefully investigated. Well dispersed CNTs in acetone were mixed with an ester of BPA under constant magnetic stirring conditions. Samples of tablet shape were prepared for testing static and dynamic performance of the composite using a nano-indentation technique. Considerable enhancement by 55 and 22% in the static elastic modulus and hardness of BPA-CNT composites, respectively, was observed (compared with that of pristine BPA). The storage modulus and tan-delta of the nanocomposites were also improved by 14 and 46%, respectively. Improved static and dynamic performance, reported in this work, significantly enhances the scope of utilization of BPA-CNT-based nanocomposites under severe static and dynamic loading conditions simultaneously. Static and dynamical analysis of CNT-reinforced epoxy provides more realistic understanding of the mechanical performance of the nanocomposite. Density functional theory (using QuantumATK software) simulations were performed to investigate and identify the alterations in the atomic morphology of CNTs during interfacial interaction with the acetone molecule and epoxy matrix. The calculations predicted that CNTs with mild defects as compared to pristine CNTs were better suited for synthesis of the nanocomposite and also assisted in a homogeneous distribution of CNTs in BPA without aggregation (with acetone as the solvent). Furthermore, structural changes in CNTs after treatment with BPA and the curing agent and the role of defects are studied in detail.

20.
J Liposome Res ; 33(2): 129-143, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35730480

RESUMO

Hyaluronic Acid (HA) has been applied as an anti-ageing molecule in the form of topical products. Current topical commercial formulations of HA face the limitations of very small and stagnant skin permeation, thereby demanding enduring administration of the formulation to sustain its action. In this study, Lipid-based nanocarriers in the form of ethosomes were formulated in a 1% w/w HA strength and were extensively evaluated in vitro, ex-vivo, and in vivo parameters along with a comparison to it's commercial counterpart. The optimised ethosomes-based HA gel formulation revealed required pH (6.9 ± 0.2), small globule size (1024 ± 9 nm), zeta potential of -6.39 ± 0.2 mV, and 98 ± 1.1% HA content. The ex vivo skin permeation and deposition potenwere conferred on synthetic membrane Strat-M, Human cadaver skin, mice skin, rat skin, and pig skin, and both parameters were found to be much higher in comparison to the commercial topical formulation. Skin deposition capacity of the optimised HA formulation was further confirmed by Scan Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM) and it was observed that the developed ethosomal gel formulation got deposited more on the treated skin. The in vivo anti-ageing effect of optimised ethosomal gel on rats was found to be greater when compared to commercial formulation of HA and the developed carrier-based system proved to deliver the HA molecule in very small amounts into the systemic circulation. The results endorse the ethosomal carrier-based formulation of HA as a attractive technique for better local bioavailability of HA.


Assuntos
Ácido Hialurônico , Absorção Cutânea , Camundongos , Ratos , Humanos , Animais , Suínos , Ácido Hialurônico/metabolismo , Lipossomos/metabolismo , Pele/metabolismo , Administração Tópica , Administração Cutânea
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA