Jonathan O Martinez

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The therapeutic efficacy of systemic drug-delivery vehicles depends on their ability to evade the immune system, cross the biological barriers of the body and localize at target tissues. White blood cells of the immune system--known as leukocytes--possess all of these properties and exert their targeting ability through cellular membrane interactions. Here,(More)
Individualized medicine is the healthcare strategy that rebukes the idiomatic dogma of 'losing sight of the forest for the trees'. We are entering a new era of healthcare where it is no longer acceptable to develop and market a drug that is effective for only 80% of the patient population. The emergence of "-omic" technologies (e.g. genomics,(More)
The controlled delivery of nucleic acids to selected tissues remains an inefficient process mired by low transfection efficacy, poor scalability because of varying efficiency with cell type and location, and questionable safety as a result of toxicity issues arising from the typical materials and procedures employed. High efficiency and minimal toxicity in(More)
In the development of new nanoparticle-based technologies for therapeutic and diagnostic purposes, understanding the fate of nanoparticles in the body is crucial. We recently developed a multistage vector delivery system comprising biodegradable and biocompatible nanoporous silicon particles (first-stage microparticles [S1MPs]) able to host, protect, and(More)
Tumor extracellular matrix (ECM) represents a major obstacle to the diffusion of therapeutics and drug delivery systems in cancer parenchyma. This biological barrier limits the efficacy of promising therapeutic approaches including the delivery of siRNA or agents intended for thermoablation. After extravasation due to the enhanced penetration and retention(More)
Nanomaterials are advancing in several directions with significant progress being achieved with respect to their synthesis, functionalization and biomedical application. In this review, we will describe several classes of prototypical nanocarriers, such as liposomes, silicon particles, and gold nanoshells, in terms of their individual function as well as(More)
Nanovectors hold substantial promise in abating the off-target effects of therapeutics by providing a means to selectively accumulate payloads at the target lesion, resulting in an increase in the therapeutic index. A sophisticated understanding of the factors that govern the degradation and release dynamics of these nanovectors is imperative to achieve(More)
The careful scrutiny of drug delivery systems is essential to evaluate and justify their potential for the clinic. Among the various studies necessary for preclinical testing, the impact of degradation is commonly overlooked. In this article, we investigate the effect of fabrication (porosity and nucleation layer) and environment (buffer and pH) factors on(More)
The characterization of nanomaterials and their influence on and interactions with the biology of cells and tissues are still partially unknown. Multistage nanovectors based on mesoporous silicon have been extensively studied for drug delivery, thermal heating, and improved diagnostic imaging. Here, the short- and long-term changes occurring in human cells(More)
Nanovectors are a viable solution to the formulation of poorly soluble anticancer drugs. Their bioaccumulation in the tumor parenchyma is mainly achieved exploiting the enhanced permeability and retention (EPR) effect of the leaky neovasculature. In this paper we demonstrate that multistage nanovectors (MSV) exhibit rapid tumoritropic homing independent of(More)