Review of Contemporary Self-Assembled Systems for the Controlled Delivery of Therapeutics in Medicine.

The novel and unique design of self-assembled micro and nanostructures can be tailored and controlled through the deep understanding of the self-assembly behavior of amphiphilic molecules. The most commonly known amphiphilic molecules are surfactants, phospholipids, and block copolymers. These molecules present a dual attraction in aqueous solutions that lead to the formation of structures like micelles, hydrogels, and liposomes. These structures can respond to external stimuli and can be further modified making them ideal for specific, targeted medical needs and localized drug delivery treatments. Biodegradability, biocompatibility, drug protection, drug bioavailability, and improved patient compliance are among the most important benefits of these self-assembled structures for drug delivery purposes. Furthermore, there are numerous FDA-approved biomaterials with self-assembling properties that can help shorten the approval pathway of efficient platforms, allowing them to reach the therapeutic market faster. This review focuses on providing a thorough description of the current use of self-assembled micelles, hydrogels, and vesicles (polymersomes/liposomes) for the extended and controlled release of therapeutics, with relevant medical applications. FDA-approved polymers, as well as clinically and commercially available nanoplatforms, are described throughout the paper

Novel injectable PLGA-PEG-PLGA self-assembled hydrogels for the extended and controlled release of DNA nanocarriers to prevent secondary cataracts

Cataracts are the second leading cause of blindness worldwide. There are over 20 million cataract surgeries each year, and these cases are expected to double within the next ten years. Over 40% of adults and nearly all children develop secondary cataracts, or posterior capsule opacification (PCO), following cataract surgery. Currently, Nd:YAG laser therapy is used to treat PCO; however, laser therapy is not available worldwide and treatment may have adverse effects on surrounding ocular tissues. Thus, there is a considerable unmet need for more efficacious and convenient treatments to prevent PCO. Injectable, stimuli-responsive gels were designed using poly(lactic-co-glycolic acid)-b-poly(ethylene glycol)) triblock copolymer and poly(L-Lysine). Hydrogel formulations with lactic acid to glycolic acid ratio of 15/1, at compositions between 14 and 25% (w/v), PLGA/PEG ratio of 2/1, and PLL concentrations between 10 and 40% (w/v) allowed for over 90% light transmittance, gel formation at 35°C, and controlled release of 3DNA® nanocarriers loaded with doxorubicin with the G8 monoclonal antibody conjugated (3DNA®:DOX:G8) for over four weeks. The physical and morphological states of this novel, thermo-sensitive hydrogel can be easily tailored for the purpose of modulating drug delivery utilizing nucleic acids. This technology offers a more effective and efficient method of ocular therapy by providing controlled delivery of 3DNA conjugates designed to specifically target cells that cause PCO. Our US patent pending technology has high potential as a more efficacious delivery method for a wide range of other therapeutics to treat a number of ocular diseases

Sustained Release of Antibody-Conjugated DNA Nanocarriers from a Novel Injectable Hydrogel for Targeted Cell Depletion to Treat Cataract Posterior Capsule Opacification

Purpose: To compare a novel, sustained release formulation and a bolus injection of a targeted nanocarrier for the ability to specifically deplete cells responsible for the development of posterior capsule opacification (PCO) in week-long, dynamic cell cultures. Methods: A novel, injectable, thermosensitive poly(D,L-lactic-co-glycolic acid)-b-poly(ethylene glycol)-b-poly(D,L-lactic-co-glycolic acid) (PLGA-PEG-PLGA) triblock copolymer hydrogel was engineered for the sustained release of targeted, nucleic acid nanocarriers loaded with cytotoxic doxorubicin (G8:3DNA:Dox). Human rhabdomyosarcoma (RD) cells were used due to their expression of brain-specific angiogenesis inhibitor 1 (BAI1), a specific marker for the myofibroblasts responsible for PCO. Under constant media flow, nanocarriers were injected into cell cultures as either a bolus or within the hydrogel. Cells were fixed and stained every other day for 7 days to compare targeted depletion of BAI1+ cells. Results: The formulation transitions to a gel at physiological temperatures, is optically clear, noncytotoxic, and can release G8:3DNA:Dox nanocarriers for up to 4 weeks. In RD cell cultures, G8:3DNA:Dox nanocarriers specifically eliminated BAI1+ cells. The bolus nanocarrier dose showed significantly reduced cell depletion overtime, while the sustained release of nanocarriers showed increased cell depletion over time. By day 7, \u3c2% of BAI1+ cells were depleted by the bolus injection and 74.2% BAI1+ cells were targeted by the sustained release of nanocarriers. Conclusions: The sustained release of nanocarriers from the hydrogel allows for improved therapeutic delivery in a dynamic system. This method can offer a more effective and efficient method of prophylactically treating PCO after cataract surgery

Biodiversidad 2014. Reporte de Estado y Tendencias de la Biodiversidad Continental de Colombia

Biodiversidad 2014 es el resultado de esfuerzos importantes de análisis científico, como también de coordinación nacional de información e inventario sobre la biodiversidad en Colombia y representa un adelanto en la manera de presentar datos sobre el estado de la biodiversidad, su localización y los factores de cambios, presentando escenarios posibles de sus tendencias futuras. Esto implica nuevos enfoques para la gestión ambiental, que puedan aportar nuevas formas de desarrollo que no impliquen la pérdida de las especies o los ecosistemas que habitan.Bogotá, D. C

Biodiversidad 2018. Reporte de estado y tendencias de la biodiversidad continental de Colombia

Las cifras y temáticas contenidos en el presente Reporte, aunque no son el panorama completo del estado del conocimiento de la biodiversidad en Colombia, son un compendio seleccionado de los temas que, desde el Instituto Humboldt, consideramos son relevantes y merecen ser discutidos por el público general. En muchos de los casos, las cifras no son esperanzadoras u son un llamado urgente a la acción. En otro casos son la evidencia de que se requieren acciones a nivel nacional, y más allá de esto, son muchas las iniciativas que están germinando desde los territorios, cada vez desde una mayor variedad de actores.Bogotá, D. C., Colombi