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1.
Small ; 20(27): e2303706, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38353067

RESUMO

Smart windows that can passively regulate incident solar radiation by dynamically modulating optical transmittance have attracted increasing scientific interest due to their potential economic and environmental savings. However, challenges remain in the global adoption of such systems, given the extreme variability in climatic and economic conditions across different geographical locations. Aiming these issues, a methylcellulose (MC) salt system is synthesized with high tunability for intrinsic optical transmittance (89.3%), which can be applied globally to various locations. Specifically, the MC window exhibits superior heat shielding potential below transition temperatures, becoming opaque at temperatures above the Lower Critical Solution Temperature and reducing the solar heat gain by 55%. This optical tunability is attributable to the particle size change triggered by the temperature-induced reversible coil-to-globular transition. This leads to effective refractive index and scattering modulation, making them prospective solutions for light management systems, an application ahead of intelligent fenestration systems. During the field tests, MC-based windows demonstrated a 9 °C temperature decrease compared to double-pane windows on sunny days and a 5 °C increase during winters, with simulations predicting an 11% energy savings. The ubiquitous availability of materials, low cost, and ease-of-manufacturing will provide technological equity and foster the ambition toward net-zero buildings.

2.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(1): 199-204, 2024 Feb 25.
Artigo em Chinês | MEDLINE | ID: mdl-38403622

RESUMO

Methylcellulose is a semi-flexible cellulose ether derivative, whose hydrogels are thermosensitive and reversible, with good biocompatibility and adjustable function, and its application has attracted much attention in the biomedical field. In this paper, the application of methylcellulose-based thermo-sensitive hydrogels in biomedical field was reviewed. Based on the mechanism of gelation and influencing factors of methylcellulose, this paper focused on the recent advances in biomedical applications of methylcellulose-based hydrogels, including drug delivery, regenerative medicine, and other related fields. The current achievements in these fields were summarized in the form of lists in this paper to provide ideas and tendencies for future research. Finally, the future development of multifunctional methylcellulose-based hydrogel materials with improved performance was also discussed.


Assuntos
Hidrogéis , Metilcelulose , Sistemas de Liberação de Medicamentos
3.
Int Arch Allergy Immunol ; 184(2): 111-121, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36323243

RESUMO

INTRODUCTION: Symptoms of allergic rhinitis can be reduced by nonpharmacological nasal sprays that create a barrier between allergens and the nasal mucosa. A new nasal spray (AM-301) containing the clay mineral bentonite was tested for its ability to reduce symptoms of grass pollen. METHODS: This open-label, crossover, noninferiority trial compared the efficacy and safety of AM-301 to that of hydroxypropyl methylcellulose (HPMC; Nasaleze® Allergy Blocker), an established barrier method. Adults with seasonal allergic rhinitis were exposed to Dactylis glomerata pollen, in a controlled setting, the Fraunhofer allergen challenge chamber, first without protection and then protected by HPMC or AM-301 (7 days apart). Efficacy was assessed from total nasal symptom score (TNSS), nasal secretion weight, and subjective rating. The primary endpoint was the difference, between AM-301 and HPMC, in least square mean change in TNSS over a 4-h exposure to allergen. RESULTS: The study enrolled 36 persons, and 35 completed all study visits. The mean TNSS was 5.91 (SD = 1.45) during unprotected exposure, 5.20 (SD = 1.70) during protection with HPMC, and 4.82 (SD = 1.74) during protection with AM-301. The difference in least square means between the two treatments was -0.39 (95% CI: -0.89 to 0.10), establishing the noninferiority of AM-301. No difference in mean weight of nasal secretions was observed between the treatments. Efficacy was rated as good or very good for AM-301 by 31% and for HPMC by 14% of subjects. Sixteen subjects reported adverse events with a relationship to AM-301 or HPMC; most adverse events were mild, and none was serious. DISCUSSION/CONCLUSION: AM-301 demonstrated noninferiority toward HPMC in the primary endpoint and was perceived better in subjective secondary endpoints. Both barrier-forming products had a persisting protective effect over 4 h and were safe.


Assuntos
Rinite Alérgica Sazonal , Rinite Alérgica , Adulto , Humanos , Sprays Nasais , Rinite Alérgica Sazonal/tratamento farmacológico , Rinite Alérgica Sazonal/prevenção & controle , Alérgenos/uso terapêutico , Mucosa Nasal , Método Duplo-Cego , Administração Intranasal
4.
Mol Pharm ; 20(8): 4196-4209, 2023 08 07.
Artigo em Inglês | MEDLINE | ID: mdl-37358932

RESUMO

In an earlier investigation, the critical cooling rate to prevent drug crystallization (CRcrit) during the preparation of nifedipine (NIF) amorphous solid dispersions (ASDs) was determined through a time-temperature transformation (TTT) diagram (Lalge et al. Mol. Pharmaceutics 2023, 20 (3), 1806-1817). The current study aims to use the TTT diagram to determine the critical cooling rate to prevent drug nucleation (CRcrit N) during the preparation of ASDs. ASDs were prepared with each polyvinylpyrrolidone (PVP) and hydroxypropyl methylcellulose acetate succinate (HPMCAS). The dispersions were first stored under conditions promoting nucleation and then heated to the temperature that favors crystallization. The crystallization onset time (tC) was determined by differential scanning calorimetry and synchrotron X-ray diffractometry. TTT diagrams for nucleation were generated, which provided the critical nucleation temperature (50 °C) and the critical cooling rate to avoid nucleation (CRcrit N). The strength of the drug-polymer interactions as well as the polymer concentration affected the CRcrit N, with PVP having a stronger interaction than HPMCAS. The CRcrit of amorphous NIF was ∼17.5 °C/min. The addition of a 20% w/w polymer resulted in CRcrit of ∼0.05 and 0.2 °C/min and CRcrit N of ∼4.1 and 8.1 °C/min for the dispersions prepared with PVP and HPMCAS, respectively.


Assuntos
Polímeros , Povidona , Temperatura , Povidona/química , Polímeros/química , Cristalização , Transição de Fase , Solubilidade , Metilcelulose/química , Estabilidade de Medicamentos
5.
Int J Mol Sci ; 25(1)2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38203527

RESUMO

Due to their unique three-dimensional structure, DNA or RNA oligonucleotide aptamers bind to various molecules with high affinity and specificity. Aptamers, alone or in combination with antibodies, can be used to sensitively quantify target molecules by quantitative real-time polymerase chain reaction (qPCR). However, the assays are often complicated and unreliable. In this study, we explored the feasibility of performing the entire assay on wells of routinely used polypropylene PCR plates. We found that polypropylene wells efficiently bind proteins. This allows the entire assay to be run in a single well. To minimize nonspecific binding of the assay components to the polypropylene wells, we tested various blocking agents and identified methylcellulose as an effective alternative to the commonly used BSA. Methylcellulose not only demonstrates comparable or superior blocking capabilities but also offers the advantage of a well-defined composition and non-animal origin. Our findings support the utilization of aptamers, either alone or in combination with antibodies, for sensitive quantification of selected molecules immobilized in polypropylene PCR wells in a streamlined one-well qPCR assay under well-defined conditions.


Assuntos
Aptâmeros de Nucleotídeos , Polipropilenos , Anticorpos , Metilcelulose , Reação em Cadeia da Polimerase em Tempo Real
6.
Gerodontology ; 2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37665947

RESUMO

OBJECTIVES: This pilot study aimed to carry out preliminary tests of the removability of an artificial biofilm equivalent (ABE) and to verify the reproducibility of the ABE testing protocol for a planned main study. BACKGROUND: There is a lack of data to develop suitable artificial biofilm substitutes, which may be helpful to perform denture hygiene education and to carry out in vitro examinations of oral hygiene products. MATERIALS AND METHODS: This single-group, prospective, longitudinal, interventional pilot study was conducted in Dresden (Germany) from February until December 2020. Participants were recruited who wore fully functional upper complete dentures. Denture biofilm was grown on acrylic specimens by wearing dentures for 12 h and 36 h using intraoral appliances. Acrylic specimens were coated with ABEs of three compositions: chitosan (ChS) 0.3 g, methylcellulose (MC) 1.7 g; ChS 0.2 g, MC 1.8 g; ChS 0.1 g, MC 1.9 g (labelled 1.7MC, 1.8MC and 1.9MC, respectively). All specimens underwent standardised mechanical brushing. The percentages of remaining biofilm (POB) were measured. RESULTS: Thirty-one participants were prescreened, and eight (26%) were included. The appliances were well tolerated, and biofilm was collected. ABE was prepared and brushed as planned. Three and six brushing strokes were needed to remove 12-h and 36-h natural denture biofilm, respectively. Correspondingly, three brushing strokes were needed to remove 1.9MC ABE and six brushing strokes to remove 1.8MC and 1.7MC ABE. A reproducibility of ABE removal was indicated. CONCLUSION: The removability of ABE and the ABE testing protocol were feasible and reproducible for conducting the future main study.

7.
Polim Med ; 53(2): 111-116, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38054367

RESUMO

BACKGROUND: Many substances are used to increase the viscosity of eye drops and reduce their surface tension. Their function is to prolong the persistence of the product on the surface of the eyeball and to increase the bioavailability of the pharmacologically active ingredient. OBJECTIVES: To investigate the surface tension of substances added to the eye drops, with the main aim of modulating properties of the preparation. MATERIAL AND METHODS: Five substances contained in solutions proposed for the development of eye drops were studied: sodium hyaluronate macromolecular (H-Na W), sodium hyaluronate ultramolecular (H-Na UM), hyaluronic acid 4% (K-H), methylcellulose (MC), and polyacrylic acid (PA). The main method was to study the surface tension using the du Noüy ring tensiometer. RESULTS: The research presented in this paper shows the various effects of different eye drop ingredients on the surface tension of the solutions. The surface tension values of PA solutions are in the range of 48.89-56.03 mN/m, of MC in the range of 68.94-89.32 mN/m, of K-H 54.54-65.66 mN/m, of H-Na UM 67.18-70.97 mN/m, and of H-Na W 67.09-71.73 mN/m. CONCLUSIONS: The use of different polymers affects the surface tension of model solutions proposed for use in ophthalmic preparations. Compounds containing carboxyl groups and anionic polymers have a similar effect on reducing the surface tension of the solution as classical surfactant compounds.


Assuntos
Ácido Hialurônico , Polímeros , Soluções Oftálmicas , Tensão Superficial , Viscosidade
8.
Drug Dev Ind Pharm ; 48(11): 646-656, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36469628

RESUMO

OBJECTIVE: To study the new formulation and technology of composite cellulose-based enteric capsule shell with one-time dipping molding without organic solvent. METHODS: Hydroxypropyl methylcellulose phthalate-55S (Hp55S) was used as the main film-forming material, agar as gelling agent, and hydroxypropyl methylcellulose (HPMC) as disintegrating regulator. The preparation technology was as follows: ① Hp55S was dissolved in dilute ammonia solution with pH of 10 ∼ 11 at room temperature to obtain transparent Hp55S solution. ② The mixture of HPMC, KCl, and Tween-80 was fully dispersed in the agar solution at 90 ∼ 100 °C and cooled to 50 ∼ 55 °C under continuous stirring to obtain a transparent agar/HPMC solution. ③The Hp55S solution was heated to 50 ∼ 55 °C and poured into the agar/HPMC solution and stirred evenly to obtain the composite cellulose solution, which was kept at 50 ∼ 55 °C for standby. ④The composite cellulose-based enteric capsule shells were prepared by dipping, spinning, drying, stripping and trimming, and joining. RESULTS: The composite cellulose-based enteric capsule shell prepared according to this formula and process met the quality requirements of 'enterosoluble vacant capsules' in Chinese Pharmacopeia. CONCLUSION: Compared with the traditional formula and preparation technology of enteric capsule shell, the product is a plant type enteric capsule shell, no organic solvent is used in the formula, and the forming steps of multiple dipping solution is not used in the process. The advantages of this study are that the production steps are simplified, the production process is environmentally friendly, and the production cost is reduced.


Assuntos
Celulose , Química Farmacêutica , Ágar , Metilcelulose , Derivados da Hipromelose , Tecnologia , Solventes , Cápsulas
9.
Int J Mol Sci ; 23(19)2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36233321

RESUMO

The Bletilla striata Polysaccharide (BSP), a natural polysaccharide derived from the east Asian terrestrial orchid Bletilla striata, is an anti-inflammatory, antiviral, and antioxidant polysaccharide. Traditionally, it has been used to treat hemostasis and for wound healing. In this study, BSP was blended with methylcellulose (MC) and methylparaben (MP) to create a hydrogel through a self-assembly route as a wound dressing. The developed hydrogels were designed as M2Bx, M5Bx, and M8Bx. M stands for MC, and the number represents a percentage. Whereas the second letter of B stands for BSP, and x refers to the percentage variation of BSP: x = 0.5%, 1%, and 2%. All the developed MB hydrogels contained ß-glucopyranosyl and α-mannopyranosyl, and rheology test had a tan δ value ≥ 0.5. The pore sizes of the hydrogels decreased by increasing the MC and BSP content, and they had better properties with respect to water loss and their swelling ratio. Evaluations in vitro and in vivo showed that all of the developed MB hydrogels have good cell viability and wound-healing properties. The M8B2 hydrogel group was found to be superior to the others from within the developed MB hydrogels. Therefore, we believe that the M8B2 hydrogel formulation has a high potential for development as a wound dressing.


Assuntos
Bandagens , Hidrogéis , Orchidaceae , Polissacarídeos , Anti-Inflamatórios , Antioxidantes , Antivirais , Hidrogéis/farmacologia , Metilcelulose , Orchidaceae/química , Polissacarídeos/farmacologia , Água
10.
Molecules ; 27(9)2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35566103

RESUMO

Intelligent packaging with indicators that provide information about the quality of food products can inform the consumer regarding food safety and reduce food waste. A solid material for a pH-responsive indicator was developed from hydroxypropyl methylcellulose (HPMC) composited with microcrystalline cellulose (MCC). MCC at 5%, 10%, 20%, and 30% w/w was introduced into the HPMC matrix and the physical, barrier, thermal, and optical properties of the HPMC/MCC bio-composite (HMB) films were analyzed. At 5, 10, and 20% MCC, improved mechanical, transparency, and barrier properties were observed, where HMB with 20% of MCC (H20MB) showed the best performance. Therefore, H20MB was selected as the biodegradable solid material for fabricating Roselle anthocyanins (RA) pH sensing indicators. The performance of the RA-H20MB indicator was evaluated by monitoring its response to ammonia vapor and tracking freshness status of chicken tenderloin. The RA-H20MB showed a clear color change with respect to ammonia exposure and quality change of chicken tenderloin; the color changed from red to magenta, purple and green, respectively. These results indicated that RA-H20MB can be used as a biodegradable pH sensing indicator to determine food quality and freshness.


Assuntos
Hibiscus , Eliminação de Resíduos , Amônia , Animais , Antocianinas/química , Celulose , Galinhas , Alimentos , Embalagem de Alimentos/métodos , Hibiscus/química , Concentração de Íons de Hidrogênio , Derivados da Hipromelose/química
11.
Molecules ; 27(19)2022 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-36235217

RESUMO

The aim of this study was to synthesize silver nanoparticles (AgNPs) using cellulose derivatives and to evaluate their antimicrobial potential. As effective reducing and stabilizing agents for AgNPs, cellulose derivatives, such as hydroxypropyl cellulose (HPC), methylcellulose (MC), ethylcellulose (EC), and cellulose acetate (CA), were used. Their ability to reduce silver ions as well as the size of the resulting AgNPs were compared. The formation and stability of the reduced AgNPs in the solution were monitored using UV-Vis analysis. The size, morphology, and charge of the AgNPs were evaluated. We found that, when using cellulosic derivatives, AgNPs with sizes ranging from 17 to 89 nm and different stabilities were obtained. The parameters, such as size and ζ potential indicate the stability of AgNPs, with AgNPs-CA and AgNPs-HPC being considered more stable than AgNPs-EC and AgNPs-MC since they show higher ζ potential values. In addition, the AgNPs showed antimicrobial activity against all reference strains and clinical isolates. MIC values between 0.0312 and 0.125 mM had a bactericidal effect on both Gram-positive and Gram-negative bacteria. The fungicidal effect was obtained at a MIC value of 0.125 mM. These results may provide rational support in the design of medical gauze products, including gauze pads, rolls, and sponges.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Antibacterianos/farmacologia , Antifúngicos , Celulose , Escherichia coli , Excipientes , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Metilcelulose , Testes de Sensibilidade Microbiana , Prata/farmacologia
12.
AAPS PharmSciTech ; 23(1): 52, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35018574

RESUMO

Despite the fact that capsules play an important role in many dry powder inhalation (DPI) systems, few studies have been conducted to investigate the capsules' interactions with respirable powders. The effect of four commercially available hydroxypropyl methylcellulose (HPMC)inhalation-grade capsule types on the aerosol performance of two model DPI formulations (lactose carrier and a carrier-free formulation) at two different pressure drops was investigated in this study. There were no statistically significant differences in performance between capsules by using the carrier-based formulation. However, there were some differences between the capsules used for the carrier-free rifampicin formulation. At 2-kPa pressure drop conditions, Embocaps® VG capsules had a higher mean emitted fraction (EF) (89.86%) and a lower mean mass median aerodynamic diameter (MMAD) (4.19 µm) than Vcaps® (Capsugel) (85.54%, 5.10 µm) and Quali-V® I (Qualicaps) (85.01%, 5.09 µm), but no significant performance differences between Embocaps® and ACGcaps™ HI. Moreover, Embocaps® VG capsules exhibited a higher mean respirable fraction (RF)/fine particle fraction (FPF) with a 3-µm-sized cutoff (RF/FPF< 3 µm) (33.05%/35.36%) against Quali-V® I (28.16%/31.75%) (P < 0.05), and a higher RF/FPF with a 5-µm-sized cutoff (RF/FPF< 5 µm) (49.15%/52.57%) versus ACGcaps™ HI (38.88%/41.99%) (P < 0.01) at 4-kPa pressure drop condition. Aerosol performance variability, pierced-flap detachment, as well as capsule hardness and stiffness, may all influence capsule type selection in a carrier-based formulation. The capsule type influenced EF, RF, FPF, and MMAD in the carrier-free formulation.


Assuntos
Budesonida , Rifampina , Administração por Inalação , Aerossóis , Cápsulas , Química Farmacêutica , Inaladores de Pó Seco , Derivados da Hipromelose , Tamanho da Partícula , Pós
13.
AAPS PharmSciTech ; 23(5): 157, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35672486

RESUMO

Gastroretentive drug delivery systems (GRDDS) get retained in the stomach for a long time, thus facilitating the absorption of drugs in the upper gastrointestinal tract. However, drugs that are difficult to dissolve or unstable in an acidic environment are not suitable for GRDDS. The current study designs GRDDS combined with a self-micro-emulsifying drug delivery system (SMEDDS) for drugs with solubility or stability problems in the stomach. The model drug fenofibrate was formulated into the optimized liquid SMEDDS composed of 50 w/w% Capryol® PGMC, 40 w/w% Kolliphor® RH40, and 10 w/w% Transcutol® HP and solidified through adsorption on several porous adsorbents. In a dissolution medium at pH 1.2, the powdered SMEDDS using Fujicalin® dissolved quickly and achieved higher drug dissolution than other adsorbents. Based on these results, a gastroretentive bilayer tablet consisting of a drug release layer and a swelling layer was designed. The drug release layer was formulated with the powdered SMEDDS and hydroxypropyl methylcellulose (HPMC) as a release modifier. HPMC was also added to the swelling layer as a water-swellable polymer. The dissolution rate depended on the viscosity of the HPMC in the drug release layer. The time for 90% drug release was extended from 3.7 to 12.0 h by increasing the viscosity grade of HPMC from 0.1 to 100 K. Moreover, the tablet swelled and maintained a size comparable to a human pylorus diameter or more for at least 24 h. This GRDDS could apply to a broader range of drug candidates.


Assuntos
Sistemas de Liberação de Medicamentos , Excipientes , Fosfatos de Cálcio , Preparações de Ação Retardada , Humanos , Derivados da Hipromelose , Pós , Solubilidade , Comprimidos
14.
Small ; 17(27): e2005205, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33491913

RESUMO

Because of their lightweight structure, flexibility, and immunity to electromagnetic interference, polymer optical fibers (POFs) are used in numerous short-distance applications. Notably, the incorporation of luminescent nanomaterials in POFs offers optical amplification and sensing for advanced nanophotonics. However, conventional POFs suffer from nonsustainable components and processes. Furthermore, the traditionally used luminescent nanomaterials undergo photobleaching, oxidation, and they can be cytotoxic. Therefore, biopolymer-based optical fibers containing nontoxic luminescent nanomaterials are needed, with efficient and environmentally acceptable extrusion methods. Here, such an approach for fibers wet-spun from aqueous methylcellulose (MC) dispersions under ambient conditions is demonstrated. Further, the addition of either luminescent gold nanoclusters, rod-like cellulose nanocrystals or gold nanocluster-cellulose nanocrystal hybrids into the MC matrix furnishes strong and ductile composite fibers. Using cutback attenuation measurement, it is shown that the resulting fibers can act as short-distance optical fibers with a propagation loss as low as 1.47 dB cm-1 . The optical performance is on par with or even better than some of the previously reported biopolymeric optical fibers. The combination of excellent mechanical properties (Young's modulus and maximum strain values up to 8.4 GPa and 52%, respectively), low attenuation coefficient, and high photostability makes the MC-based composite fibers excellent candidates for multifunctional optical fibers and sensors.


Assuntos
Ouro , Metilcelulose , Celulose , Módulo de Elasticidade , Fibras Ópticas
15.
Mol Pharm ; 18(10): 3882-3893, 2021 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-34529437

RESUMO

Compression-induced destabilization was investigated in various celecoxib amorphous solid dispersions containing hydroxypropyl methylcellulose (HPMC), poly(vinylpyrrolidone)/vinyl acetate copolymer (PVP/VA), or poly(vinylpyrrolidone) (PVP) at a concentration range of 1-10% w/w. Pharmaceutically relevant (125 MPa pressure with a minimal dwell time) and extreme (500 MPa pressure with a 60 s dwell time) compression conditions were applied to these systems, and the changes in their physical stability were monitored retrospectively (i.e., in the supercooled state) using dynamic differential scanning calorimetry (DSC) and low-frequency Raman (LFR) measurements over a broad temperature range (-90 to 200 and -150 to 140 °C, respectively). Both techniques revealed similar changes in the crystallization behavior between samples, where the application of a higher compression force of 500 MPa resulted in a more pronounced destabilization effect that was progressively mitigated with increasing polymer content. However, other aspects such as more favorable intermolecular interactions did not appear to have any effect on reducing this undesirable effect. Additionally, for the first time, LFR spectroscopy was used as a viable technique to determine the secondary or local glass-transition temperature, Tg,ß, a major indicator of the physical stability of neat amorphous pharmaceutical systems.


Assuntos
Celecoxib/química , Composição de Medicamentos , Estabilidade de Medicamentos , Varredura Diferencial de Calorimetria , Cristalização , Derivados da Hipromelose/química , Povidona/química , Pressão , Pirrolidinas , Análise Espectral Raman , Compostos de Vinila
16.
Macromol Rapid Commun ; 42(3): e2000497, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33205538

RESUMO

Functional polymer, especially the one based on renewable and sustainable materials, has attracted increasing attention to satisfy the growing demand for the design of stimuli-responsive devices. Methylcellulose (MC) is a water-soluble derivative of cellulose, which has been widely used in many fields for its biocompatibility and biological inertness. In this work, MC is labeled by tetraphenylethylene (TPE) via azide-alkyne click reaction to obtain a fluorescent cellulose-based derivative of MC-TPE. The degree of substitution of MC-TPE is determined to be 0.074, which can be self-assembled into micelles in water with the size of 42 ± 6 nm. MC-TPE shows thermoresponsivity and thermoreversibility in size, transmittance, and fluorescence, enabling it to work as a fluorescent thermosensor. Moreover, MC-TPE exhibits nontoxicity and biocompatibility, allowing its application in MCF-7 cell imaging. Therefore, this newly functional natural polymer shows promising potentials in the fields of sensing and bioimaging.


Assuntos
Metilcelulose , Estilbenos , Corantes Fluorescentes , Polímeros
17.
Biopharm Drug Dispos ; 42(2-3): 78-84, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33400825

RESUMO

The present study was aimed to develop a novel sustained-release formulation for allopurinol (ALP/SR) with the use of a pH-sensitive polymer, hydroxypropyl methylcellulose acetate succinate, to reduce nephrotoxicity. ALP/SR was evaluated in terms of crystallinity, the dissolution profile, pharmacokinetic behavior, and nephrotoxicity in a rat model of nephropathy. Under acidic conditions (pH1.2), sustained release behavior was seen for ALP/SR, although both crystalline ALP and ALP/SR exhibited rapid dissolution at neutral condition. After multiple oral administrations of ALP samples (10 mg-ALP/kg) for 4 days in a rat model of nephropathy, ALP/SR led to a low and sustained plasma concentration of ALP, as evidenced by half the maximum concentration of ALP and a 2.5-fold increase in the half-life of ALP compared with crystalline ALP, possibly due to suppressed dissolution behavior under acidic conditions. Repeated-dosing of ALP/SR resulted in significant reductions in plasma creatinine and blood urea nitrogen levels by 73% and 69%, respectively, in comparison with crystalline ALP, suggesting the low nephrotoxic risk of ALP/SR. From these findings, a strategic SR formulation approach might be an efficacious dosage option for ALP to avoid severe nephrotoxicity in patients with nephropathy.


Assuntos
Alopurinol/farmacocinética , Supressores da Gota/farmacocinética , Metilcelulose/análogos & derivados , Administração Oral , Alopurinol/efeitos adversos , Alopurinol/sangue , Alopurinol/química , Animais , Antineoplásicos , Nitrogênio da Ureia Sanguínea , Cisplatino , Creatinina/sangue , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Liberação Controlada de Fármacos , Supressores da Gota/efeitos adversos , Supressores da Gota/sangue , Supressores da Gota/química , Meia-Vida , Rim/efeitos dos fármacos , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Masculino , Metilcelulose/química , Metilcelulose/farmacocinética , Ratos Sprague-Dawley
18.
J Wound Care ; 30(Sup9a): IVi-IVx, 2021 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-34597167

RESUMO

AIM: Self-healing, swellable and biodegradable polymers are vital materials that may facilitate the different stages of wound healing. The aim of this research was to prepare wound healing films using self-healing polyvinyl alcohol (PVA), swellable hydroxypropyl methylcellulose (HPMC), biodegradable polyglycolic acid (PGA) sutures and ciprofloxacin antibiotic for improved treatment outcome. METHODS: Films were formulated through aqueous-based mixing of varying amounts of polyvinyl alcohol (10-20% weight/weight (w/w)) and hydroxypropyl methylcellulose (0.5, 1% w/w) with fixed quantities of ciprofloxacin. PGA sutures were placed as grids within the wet mixtures of the polymers and ciprofloxacin, and thereafter products were air dried. The formulated films were evaluated for swelling ratio, breaking elongation, folding endurance, moisture uptake and loss, compatibility and in vitro antibiotic release. Furthermore, in vivo wound healing was studied using excision model and histopathological examinations. RESULTS: Swelling ratios were above 1.0 and the films were minimally stretchable, with folding endurance greater than 500. Films were stable while moisture uptake and loss were observed to be less than 30%. Among the optimised hydrogel batches, those containing 10% w/w PVA and 1% w/w HPMC with no PGA showed the highest drug release of 73%, whereas the batches with higher PGA content showed higher percentage wound size reduction with minimal scar. The completeness of wound healing with batches containing PVA, HPMC, ciprofloxacin and PGA, along with the standard, is evident considering the massive cornification, regeneration of the epithelial front and stratum spinosum. CONCLUSION: The findings show that polymer-based multifunctional composite films are suitable for use as dressings for improved wound healing.


Assuntos
Ciprofloxacina , Polímeros , Bandagens , Hidrogéis , Cicatrização
19.
Molecules ; 26(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204472

RESUMO

The ostrich oil of Struthio camelus (Ratite) found uses in folk medicine as an anti-inflammatory in eczema and contact dermatitis. The anti-inflammatory effect of a γ-lactone (5-hexyl-3H-furan-2-one) isolated from ostrich oil and its formulated nano-emulsion in formalin-induced paw edema was investigated in this study. Ostrich oil was saponified using a standard procedure; the aqueous residue was fractionated, purified, and characterized as γ-lactone (5-hexyl-3H-furan-2-one) through the interpretation of IR, NMR, and MS analyses. The γ-lactone was formulated as nano-emulsion using methylcellulose (MC) for oral solubilized form. The γ-lactone methylcellulose nanoparticles (γ-lactone-MC-NPs) were characterized for their size, shape, and encapsulation efficiency with a uniform size of 300 nm and 59.9% drug content. The γ-lactone was applied topically, while the formulated nanoparticles (NPs) were administered orally to rats. A non-steroidal anti-inflammatory drug (diclofenac gel) was used as a reference drug for topical use and ibuprofen suspension for oral administration. Edema was measured using the plethysmograph method. Both γ-lactone and γ-lactone-MC-NPs showed reduction of formalin-induced paw edema in rats and proved to be better than the reference drugs; diclofenac gel and ibuprofen emulsion. Histological examination of the skin tissue revealed increased skin thickness with subepidermal edema and mixed inflammatory cellular infiltration, which were significantly reduced by the γ-lactone compared to the positive control (p-value = 0.00013). Diuretic and toxicity studies of oral γ-lactone-MC-NPs were performed. No diuretic activity was observed. However, lethargy, drowsiness, and refusal to feeding observed may limit its oral administration.


Assuntos
Lactonas/isolamento & purificação , Lactonas/farmacologia , Struthioniformes/metabolismo , Administração Oral , Administração Tópica , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/farmacologia , Diclofenaco/administração & dosagem , Diclofenaco/farmacologia , Edema/tratamento farmacológico , Emulsões/farmacologia , Formaldeído/efeitos adversos , Ibuprofeno/administração & dosagem , Ibuprofeno/farmacologia , Masculino , Paleógnatas/metabolismo , Ratos , Ratos Wistar , Pele/efeitos dos fármacos
20.
Molecules ; 26(16)2021 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-34443511

RESUMO

Tannin content in red wines is positively correlated with astringency perception and wine grade; however, tannin quantification is one of the main challenges. In this study, tannin content was quantified using three analytical methods in commercial red wines from Vitis vinifera and interspecific cold-hardy hybrids including Marquette, Frontenac, and Petite pearl cultivars. Protein (PP) and methylcellulose precipitation (MCP) methods were compared to a HPLC-DAD method, which is based on the interaction between tannins and a hydrophobic surface (RPC). Frontenac wines were the poorest in tannins and Cabernet sauvignon wines were the richest regardless of the method used. In cold-hardy red wines, the tannin content was higher in Marquette with high alcohol content, which suggested that the tannins were extracted from seeds rather than skins. The high limit of quantification of the PP method and the presence of anthocyanin di-glucosides in cold-hardy wines were parameters suggesting that protein and methylcellulose precipitation methods were neither suitable nor reliable for the quantification of tannins in cold-hardy red wines. The tannin content quantified by RPC was positively correlated to tannin quantified by MCP, suggesting that the RPC method would be relevant for the quantification of tannins in red wines.


Assuntos
Sementes/química , Taninos/química , Vitis/química , Vinho/análise , Bebidas Alcoólicas/análise , Antocianinas/química , Cromatografia Líquida de Alta Pressão , Frutas/química , Especificidade da Espécie , Taninos/isolamento & purificação
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