Fifty-kDa Hyaluronic Acid Upregulates Some Epidermal Genes without Changing TNF-α Expression in Reconstituted Epidermis

Background: Due to its strong water binding potential, hyaluronic acid (HA) is a well-known active ingredient for cosmetic applications. However, based on its varying molecular size, skin penetration of HA may be limited. Recent studies have demonstrated that low-molecular-weight HA (LMW HA) may show a certain proinflammatory activity. We thus aimed to characterize an LMW-sized HA molecule that combines strong anti-aging abilities with efficient skin penetration but lacks potential proinflammatory effects. Methods: Total RNA and total protein were isolated from reconstituted human epidermis following incubation with HAs of various molecular weights (20, 50, 130, 300, 800 and 1,500 kDa). Tumor necrosis factor-alpha expression was determined using quantitative PCR. Genonnic and proteomic expression of various junctional proteins was determined using Affymetrix and common Western blotting techniques. Results: LMW HA of approximately 50 kDa did not significantly alter tumor necrosis factor-alpha expression compared to 20-kDa HA, but revealed significantly higher skin penetration rates than larger sized HA associated with increased expression of genes and proteins known to be involved in tight junction formation and keratinocyte cohesion. Conclusion: LMW HA of approximately 50 kDa shows better penetration abilities than larger-sized HA. In addition, LMW HA influences the expression of various genes including those contributing to keratinocyte differentiation and formation of intercellular tight junction complexes without showing proinflammatory activity. These observations contribute to current knowledge on the effects of LMW HA on keratinocyte biology and cutaneous physiology. Copyright (C) 2011 S. Karger AG, Base

Kitozanski umetci za periodontitis: Utjecaj količine lijeka, plastifikatora i umrežavanja na oslobađanje metronidazola in vitro

Chitosan based metronidazole (MZ) inserts were fabricated by the casting method and characterized with respect to mass and thickness uniformity, metronidazole loading and in vitro metronidazole release kinetics. The fabricated inserts exhibited satisfactory physical characteristics. The mass of inserts was in the range of 5.63 ± 0.42 to 6.04 ± 0.89 mg. The thickness ranged from 0.46 ± 0.06 to 0.49 ± 0.08 mm. Metronidazole loading was in the range of 0.98 ± 0.09 to 1.07 ± 0.07 mg except for batch CM3 with MZ loading of 2.01 ± 0.08 mg. The inserts exhibited an initial burst release at the end of 24 h, irrespective of the drug to polymer ratio, plasticizer content or cross-linking. However, further drug release was sustained over the next 6 days. Cross-linking with 10% (m/m) of glutaraldehyde inhibited the burst release by ~30% and increased the mean dissolution time (MDT) from 0.67 to 8.59 days. The decrease in drug release was a result of reduced permeability of chitosan due to cross-linking.Umetci metronidazola na bazi kitozana napravljeni su kasting metodom. Proučavana je ujednačenost mase i debljine, količina ljekovite tvari i kinetika oslobađanja metronidazola in vitro. Fizičke karakteristike umetaka bile su zadovoljavajuće: masa je bila u rasponu 5,63 ± 0,42 – 6,04 ± 0,89 mg, debljina od 0.46 ± 0.06 – 0.49 ± 0.08 mm with, količina metronidazola od 0,98 ± 0,09 – 1,07 ± 0,07 mg. Nakon 24 h iz svih umetaka, neovisno o omjeru ljekovite tvari i polimera, količini plastifikatora ili umrežavanju, dio metronidazola se naglo oslobodio. Međutim, daljnje oslobađanje je bilo polagano tijekom 6 dana. Umrežavanje s 10% (m/m) otopinom glutaraldehida spriječilo je naglo oslobađanje za ~30% i povećalo je srednje vrijeme oslobađanja (MDT) s 0,67 na 8,59 dana. Smanjenje u oslobađanju ljekovite tvari posljedica je smanjenja permeabilnosti umreženog kitozana

Is there a role for herbal medicine in the treatment and management of periodontal disease?

Periodontal disease is an inflammatory condition of the tissues of the periodontium that affects up to 90% of the world’s population. Emerging antibiotic and antimicrobial resistance in oral biofilms has sparked off an increased interest in the potential of medicinal plants to treat periodontal pathologies. The last decade has seen a surge in numbers of in vitro and in vivo studies on herbs traditionally used for their anti-bacterial properties in ethno-pharmacological applications. This review paper assesses the current status and role of medicinal plants in the treatment and management of periodontal disease

Poly(Ortho Esters): Recent Developments for Biomedical Applications

Poly(ortho esters) (POE) are hydrophobic and bioerodible polymers that have been under development since the early 1970s. Up to now, four generations of such polymers have been described. Of most interest are poly(ortho esters) III and poly(ortho esters) IV. POE III is a semi-solid material that has been shown to be highly biocompatible and is currently being investigated as a carrier for sustained drug delivery to treat diseases of the posterior segment of the eye. However, the polymerization is difficult to control and is not readily scaled up. POE IV can be easily prepared in a highly reproducible manner, is very stable provided moisture is rigorously excluded and has also been shown to be biocompatible. It is currently under development for a variety of applications, such as ocular delivery, protein release, and periodontal disease treatment

Hyaluronic Acid Based Hydrogels for Regenerative Medicine Applications

Hyaluronic acid (HA) hydrogels, obtained by cross-linking HA molecules with divinyl sulfone (DVS) based on a simple, reproducible, and safe process that does not employ any organic solvents, were developed. Owing to an innovative preparation method the resulting homogeneous hydrogels do not contain any detectable residual cross-linking agent and are easier to inject through a fine needle. HA hydrogels were characterized in terms of degradation and biological properties, viscoelasticity, injectability, and network structural parameters. They exhibit a rheological behaviour typical of strong gels and show improved viscoelastic properties by increasing HA concentration and decreasing HA/DVS weight ratio. Furthermore, it was demonstrated that processes such as sterilization and extrusion through clinical needles do not imply significant alteration of viscoelastic properties. Both SANS and rheological tests indicated that the cross-links appear to compact the network, resulting in a reduction of the mesh size by increasing the cross-linker amount. In vitro degradation tests of the HA hydrogels demonstrated that these new hydrogels show a good stability against enzymatic degradation, which increases by increasing HA concentration and decreasing HA/DVS weight ratio. Finally, the hydrogels show a good biocompatibility confirmed by in vitro tests