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African dust incursions in the Caribbean Region: dust concentrations, chemical composition, and fungal spore concentrations
(2021-05-18)
African dust can be transported over thousands of kilometers through the Atlantic Ocean reaching the Caribbean region, Central América, and parts of the southern USA mostly in the summer months. Dust emissions from ...
Development of targeted formulations for the delivery of a cytochrome c-based drug for application in cancer therapy
(2021-05-13)
The progression of a cell toward apoptosis, upon cellular stress, is accompanied by a set of characteristic events which includes permeabilization of the mitochondrial outer membrane and release of cytochrome c into the ...
Exploring the formation of guanosine-based colloidal particles and their affinity towards targeted molecules
(2021-06-30)
The ultimate goal of stimuli-responsive drug delivery systems is the encapsulation and release of biologically relevant molecules (e.g., drugs, proteins) with spatiotemporal control. In order to do this, delivery systems ...
Nicotinic acetylcholine receptor solubilization using lipid analog detergents: A key aspect toward receptor crystallization and functional characterization.
(2018-12)
The nicotinic acetylcholine receptor (nAChR) is a ligand-gated ion channel (LGIC) composed of five subunits (2α, 1β, 1γ, and 1δ) in a pentameric arrangement. The nAChR is a crucial component of the cholinergic pathway and manages the synaptic transmission between the brain and muscle. During the past five decades, the nAChR from T. californica has been extensively studied and used as a representative model for crystallization trials. There have been several accomplishments in the nAChR crystallization efforts, particularly using Cryo-EM and molecular engineering coupled with hanging drop crystallography. However, a high-resolution crystal structure of the native nAChR has not yet been developed, in part due to the poor understanding of the lipid-protein-detergent interactions occurring within the receptor. Lipidic matrixes as crystallization environments for membrane proteins have been used to improve the yield of membrane protein’s crystal structures. Nevertheless, little is known about the effect of the isolation methodologies (i.e., detergents, buffers, and endogenous lipid composition) towards the LCP. Our laboratory designed a lipid-based characterization approach and examined the stability, functionality, and mobility of the T. californica nAChR. Size exclusion chromatography was used to assay soluble stability, two electron voltage clamp (TEVC) to study ion channel functionality, and fluorescence recovery after photobleaching (FRAP) to assess nAChR mobility on the LCP. The evaluation of these criteria is essential to determine the appropriate conditions to conduct nAChR crystallization. Our studies showed it is possible to extract T. californica nAChR by employing lipid analog detergents and provided valuable insights for the preparation of functionally active nAChR-detergent complexes. We demonstrated that phospholipid-analog detergents with 16 carbon chains sustain nAChR function and stability....
Biologically relevant formulation and expansion of responsive properties of guanine based supramolecular particles.
(2021-01-14)
Colloidal particles ranging from the nano to the microscale show great promise in the delivery and enhancement of therapeutic agents. The formulation of many of these particles usually includes crosslinkers, non-biocompatible ...
Nanosized Core-Shell Protein Drug Delivery Systems
(2019-05)
Proteins have the complexity and specificity to be effective therapeutics. However, the same complexity that confer proteins with high specificity makes them susceptible to stability problems, immunogenicity, or rapid ...
Design of responsive cellulose-block copolymer memebranes for the remediation of organic emerging contaminants: a selective adsorption approach for electron-deficient aromatic compounds.
(2019-08)
Organic emerging contaminants (OECs) or contaminants of emerging concern (CECs) are molecules that were previously unaccounted for in term of water quality standards and are known now to have adverse ecological and human ...
Chemically modified polymeric substrates for aqueous molecular separations: applications to water treatment
(2020-05-05)
Even though we live in a planet which has a surface composition of 70% water,
less than 1% is in the form of freshwater. Changes in society, population growth, and
industrialization have significantly increased the water ...
Single entity electrochemistry of hard and soft nanoparticles using direct particle coulometry, blocking, and catalytic amplification methods.
(2021-05-10)
In the last decades, single entity electrochemistry (SEE) has emerged as a powerful technique allowing for characterization of nanoparticles, detection of molecules, enzymes, cells, viruses, and even one single atom at a ...
From environmental remediation to photoelectrochemical cell applications: Fe0/ FexOy, CdFe2O4, and NiFe2O4 nanoparticles and the development of an electrochemical system for ammonia oxidation reaction at the international space station
(2021-05-14)
Contaminated water bodies have been identified in the industrialized area of the north area of Puerto Rico. The excessive construction without considering the diversity of the ecosystem that encompasses the north area has ...