Hydrogel-Based Microneedle as a Drug Delivery System.

The skin is considered the largest and most accessible organ in the human body, and allows the use of noninvasive and efficient strategies for drug administration, such as the transdermal drug delivery system (TDDS). TDDSs are systems or patches, with the ability and purpose to deliver effective and therapeutic doses of drugs through the skin. Regarding the specific interaction between hydrogels (HG) and microneedles (MNs), we seek to find out how this combination would be applied in the context of drug delivery, and we detail some possible advantages of the methods used. Depending on the components belonging to the HG matrix, we can obtain some essential characteristics that make the combination of hydrogels-microneedles (HG-MNs) very advantageous, such as the response to external stimuli, among others. Based on multiple characteristics provided by HGMNs that are depicted in this work, it is possible to obtain unique properties that include controlled, sustained, and localized drug release, as well as the possibility of a synergistic association between the components of the formulation and the combination of more than one bioactive component. In conclusion, a system based on HG-MNs can offer many advantages in the biomedical field, bringing to light a new technological and safe system for improving the pharmacokinetics and pharmacodynamics of drugs and new treatment perspectives.

The discarded cow from the flowered desert: revalidation of Gyriosomus crispaticollis Fairmaire, 1886 stat. rev. (Coleoptera: Tenebrionidae) in Southern Atacama, Chile.

Gyriosomus crispaticollis Fairmaire, 1886 is revalidated from the synonymy of Gyriosomus luczotii Guérin-Méneville, 1831 based on the study of G. crispaticollis syntypes and comparative morphological and genetic analyses. Our results suggest that G. crispaticollis is morphologically closer to Gyriosomus multigranulosus Pizarro-Araya & Flores, 2004 than G. luczotii, but genetically barely closer to G. luczotii. Also habitat preferences, field observations and lectotype designation are provided for G. crispaticollis.

Delivery Systems in Ocular Retinopathies: The Promising Future of Intravitreal Hydrogels as Sustained-Release Scaffolds.

Slow-release delivery systems are needed to ensure long-term sustained treatments for retinal diseases such as age-related macular degeneration and diabetic retinopathy, which are currently treated with anti-angiogenic agents that require frequent intraocular injections. These can cause serious co-morbidities for the patients and are far from providing the adequate drug/protein release rates and required pharmacokinetics to sustain prolonged efficacy. This review focuses on the use of hydrogels, particularly on temperature-responsive hydrogels as delivery vehicles for the intravitreal injection of retinal therapies, their advantages and disadvantages for intraocular administration, and the current advances in their use to treat retinal diseases.

Supramolecular hydrogels based on cellulose for sustained release of therapeutic substances with antimicrobial and wound healing properties.

A multifaceted hydrogel-based formulation was reported. The hydrogel was prepared by crosslinking cellulose and substituted chalcone. Moreover, the formulation was conjugated with carbon nanotubes with the aim of increasing the loading amount of bioactive compounds such as allantoin, dexpanthenol, resveratrol and linezolid. The hydrogel formation was confirmed by swelling tests, FT-IR spectroscopy, thermogravimetric analysis and SEM. The hydrogel showed an improved release rate of therapeutic substances, exhibiting a simultaneous and coordinated release according to the chromatographic studies. The efficacy of drug release was confirmed by wound closure and in vivo wound healing studies that showed promising healing results. The antibacterial assays demonstrated that the sustained release of linezolid tends to be very effective. In conclusion, a multifaceted formulation based on carbon nanotube-containing cellulose-chalcone was developed that can potentially be utilized in treating complex wounds owing to its improved wound healing properties and prevention of potential infections.

Effect of temperature on lipids, proteins, and carbohydrates levels during development from egg extrusion to juvenile stage of Cherax quadricarinatus (Decapoda: Parastacidae).

The influence of temperature on biochemical composition, survival and duration of development of Cherax quadricarinatus from egg extrusion to juvenile was analyzed. Berried females were individually subjected to each of 22, 25, 28 and 31 degrees C (n=5 per temperature). Egg samples were obtained every 3 days from egg extrusion to juvenile stage for biochemical analysis. Duration of development and survival decreased with increasing temperature. At 22 and 25 degrees C half of the initial lipid content was consumed during development. At 28 and 31 degrees C, 80% of the initial amount of lipids was consumed. For proteins, depletion rate was significantly lower at 25 degrees C (36% of the initial amount) than at 22, 28 and 31 degrees C (61-65% of the initial amount). For carbohydrates, a significant consumption was observed only at 22 degrees C. Total energy consumption was lower at 22 and 25 degrees C than at 28 and 31 degrees C. We conclude that 22-25 degrees C is the optimal temperature range for C. quadricarinatus egg incubation, although 25 degrees C might be better in terms of development duration in terms of survival, energy cost and protein consumption.