Methylcellulose and hydroxypropylmethylcellulose (hypromellose) are used in topical formulations of a protein to form a viscous hydrogel. Five lots of hypromellose raw material were made into 3% gel; all showed viscosity loss after sterilization by autoclave. EDTA (edetate disodium) minimized the viscosity loss caused by autoclaving in the presence of up to 100 ppm H(2)O(2). These results suggest that EDTA may prevent loss of viscosity of the hydrogel when peroxide is present. H(2)O(2) at low levels (2-50 ppm) caused significant viscosity loss over time at either 40 degrees C or 5 degrees C in 3% methylcellulose or hypromellose gel. EDTA slowed the rate of viscosity loss during storage under stress by H(2)O(2) but did not completely prevent the loss. Methionine was effective in completely preventing gel-viscosity loss during storage in the presence of up to 50 ppm H(2)O(2). On the basis of these results, it is recommended that methionine be added to the protein topical formulation as a stabilizer against viscosity loss.
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http://dx.doi.org/10.1208/s12249-009-9258-6 | DOI Listing |
Colloids Surf B Biointerfaces
December 2024
College of Physical, Sichuan University, Chengdu, Sichuan 610065, PR China. Electronic address:
The imbalance of redox homeostasis, especially the abnormal levels of reactive oxygen species (ROS), is a key obstacle in the bone repair process. Therefore, developing materials capable of scavenging ROS and modulating the microenvironment of bone defects is crucial for promoting bone repair. In this study, to endow poly(amino acids) (PAA) and its composites with anti-oxidative stress properties and enhanced osteogenic differentiation, we designed and prepared a calcium sulfate/calcium hydrogen phosphate/poly(amino acids) (PCDM) composite material with a thioether structure (-S-) in the molecular chain of PAA matrix through situ polymerization and physical blending method.
View Article and Find Full Text PDFSci Rep
January 2025
School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, 102488, China.
The main advantages of microneedles are precise drug delivery through human skin, minimal tissue damage and painlessness. We conducted structural analysis and skin puncture studies of hollow microneedles using ANSYS for three materials: Hafnium Dioxide (HfO), Polyglycolic acid (PGA) and Polylactic acid (PLA). Firstly, we selected three lengths, three tip diameters and three base diameters to conduct a L(3) orthogonal experiment.
View Article and Find Full Text PDFBiomed Mater
January 2025
Department of Orthopaedic Surgery, University of Connecticut, Chemical, Materials & Biomolecular Engineering MC-3711, ARB7-E7018, 263 Farmington Avenue, Farmington, CT 06032, USA, Storrs, Connecticut, 06269, UNITED STATES.
Articular cartilage and osteochondral defect repair and regeneration presents significant challenges to the field of tissue engineering (TE). TE and regenerative medicine strategies utilizing natural and synthetic-based engineered scaffolds have shown potential for repair, however, they face limitations in replicating the intricate native microenvironment and structure to achieve optimal regenerative capacity and functional recovery. Herein, we report the development of a cartilage extracellular matrix (ECM) as a printable biomaterial for tissue regeneration.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
School of Science, STEM College, RMIT University, Melbourne, Victoria 3000, Australia. Electronic address:
Egg white gels prepared through fermentation, similar to yogurt production, offer a high-protein, zero-fat alternative to traditional dairy products. This study investigated the impact of guar gum (GG) and xanthan gum (XG) as rheological modifiers on the stability of fermented egg white gels. Rheological analysis revealed that the addition of both gums significantly influenced gel properties, with XG demonstrating superior performance.
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December 2024
School of Mechanical Engineering, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250353, China.
Microtextured microneedles are tiny needle-like structures with micron-scale microtextures, and the drugs stored in the microtextures can be released after entering the skin to achieve the effect of precise drug delivery. In this study, the skin substitution model of Ogden's hyperelastic model and the microneedle array and microtexture models with different geometrical parameters were selected to simulate and analyse the flow of the microtexture microneedle arrays penetrating the skin by the finite-element method, and the length of the microneedles was determined to be 200 μm, the width 160 μm, and the value of the gaps was determined to be 420 μm. A four-pronged cone was chosen as the shape of microneedles, and a rectangle was chosen as the shape of the drug-carrying microneedle.
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