When colors mislead: Genomics and bioacoustics prompt re-classification of Asian flycatcher radiation (Aves: Niltavinae).

Traditional classification of many animals, including birds, has been highly dependent on external morphological characters like plumage coloration. However, both bioacoustics and genetic or genomic data have revolutionized our understanding of the relationships of certain lineages and led to sweeping taxonomic re-organizations. In this study, we present a case of erroneous delimitation of genus boundaries in the species-rich flycatcher subfamily Niltavinae. Genera within this subfamily have historically been delineated based on blue versus brown male body plumage until recent studies based on a few mitochondrial and nuclear loci unearthed several cases of generic misclassification. Here we use extensive bioacoustic data from 43 species and genomic data from 28 species for a fundamental reclassification of species in the Niltavinae. Our study reveals that song is an important trait to classify these birds even at the genus level, whereas plumage traits exhibit ample convergence and have led to numerous historic misattributions. Our taxonomic re-organization leads to new biogeographic limits of major genera, such that the genus Cyornis now only extends as far east as the islands of Sulawesi, Sula, and Banggai, whereas Eumyias is redefined to extend far beyond Wallace's Line to the islands of Seram and Timor. Our conclusions advise against an over-reliance on morphological traits and underscore the importance of integrative datasets.

Gene regulatory network inference with popInfer reveals dynamic regulation of hematopoietic stem cell quiescence upon diet restriction and aging.

Inference of gene regulatory networks (GRNs) can reveal cell state transitions from single-cell genomics data. However, obstacles to temporal inference from snapshot data are difficult to overcome. Single-nuclei multiomics data offer means to bridge this gap and derive temporal information from snapshot data using joint measurements of gene expression and chromatin accessibility in the same single cells. We developed popInfer to infer networks that characterize lineage-specific dynamic cell state transitions from joint gene expression and chromatin accessibility data. Benchmarking against alternative methods for GRN inference, we showed that popInfer achieves higher accuracy in the GRNs inferred. popInfer was applied to study single-cell multiomics data characterizing hematopoietic stem cells (HSCs) and the transition from HSC to a multipotent progenitor cell state during murine hematopoiesis across age and dietary conditions. From networks predicted by popInfer, we discovered gene interactions controlling entry to/exit from HSC quiescence that are perturbed in response to diet or aging.

Pro-inflammatory cytokine profile is present in the serum of Mexican patients with different stages of diabetic retinopathy secondary to type 2 diabetes.

AIM: It's been reported that pro-inflammatory cytokines are elevated in patients with diabetic retinopathy (DR); this may contribute to the pathophysiology of the disease. The aim of this study is to measure the concentration of various inflammatory cytokines from the main CD4+ T helper inflammatory responses in blood serum from Mexican patients with DR in different stages using cytometric bead array (CBA) technology and correlate them with the presence and severity of DR in order to find possible DR biomarkers that serve as diagnostic or therapeutic predictors. METHODS: 64 subjects were included in the study, 16 in the control group, 16 in the type 2 diabetes mellitus no DR (NDR) group, 16 in the non-proliferative DR (NPDR) group and 16 in the proliferative DR (PDR) group. Cytokine concentrations of interleukin (IL) 1ß, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-17A, tumour necrosis factor alpha (TNFα) and interferon-gamma in serum samples were measured using Human Inflammatory and TH1/TH2/TH17 CBA Kit. RESULTS: IL-6, IL-12, IL-17a and TNFα were significantly higher in the patients with DR compared with the control group. The PDR group showed a slightly lower concentration of serum cytokines IL-6, IL-12 and IL-17a. TNFα showed a higher concentration compared with healthy controls, NDR and NPDR subjects. We also found a positive statistical correlation between the presence and severity of DR with the clinical parameters haemoglobin A1c, body mass index and serum creatinine and the concentration of serum cytokines IL-6 and TNFα. CONCLUSION: Our findings suggest that patients with diabetes and DR have a stronger chronic inflammatory profile compared with non-diabetic subjects.

Lysyl oxidase engineered lipid nanovesicles for the treatment of triple negative breast cancer.

In the field of oncology research, a deeper understanding of tumor biology has shed light on the role of environmental conditions surrounding cancer cells. In this regard, targeting the tumor microenvironment has recently emerged as a new way to access this disease. In this work, a novel extracellular matrix (ECM)-targeting nanotherapeutic was engineered using a lipid-based nanoparticle chemically linked to an inhibitor of the ECM-related enzyme, lysyl oxidase 1 (LOX), that inhibits the crosslinking of elastin and collagen fibers. We demonstrated that, when the conjugated vesicles were loaded with the chemotherapeutic epirubicin, superior inhibition of triple negative breast cancer (TNBC) cell growth was observed both in vitro and in vivo. Moreover, in vivo results displayed prolonged survival, minimal cytotoxicity, and enhanced biocompatibility compared to free epirubicin and epirubicin-loaded nanoparticles. This all-in-one nano-based ECM-targeting chemotherapeutic may provide a key-enabling technology for the treatment of TNBC.

Phosphoprotein-based biomarkers as predictors for cancer therapy.

Disparities in cancer patient responses have prompted widespread searches to identify differences in sensitive vs. nonsensitive populations and form the basis of personalized medicine. This customized approach is dependent upon the development of pathway-specific therapeutics in conjunction with biomarkers that predict patient responses. Here, we show that Cdk5 drives growth in subgroups of patients with multiple types of neuroendocrine neoplasms. Phosphoproteomics and high throughput screening identified phosphorylation sites downstream of Cdk5. These phosphorylation events serve as biomarkers and effectively pinpoint Cdk5-driven tumors. Toward achieving targeted therapy, we demonstrate that mouse models of neuroendocrine cancer are responsive to selective Cdk5 inhibitors and biomimetic nanoparticles are effective vehicles for enhanced tumor targeting and reduction of drug toxicity. Finally, we show that biomarkers of Cdk5-dependent tumors effectively predict response to anti-Cdk5 therapy in patient-derived xenografts. Thus, a phosphoprotein-based diagnostic assay combined with Cdk5-targeted therapy is a rational treatment approach for neuroendocrine malignancies.

Evaluación de la calidad microbiológica de productos naturales procesados de uso medicinal comercializados en Quito, Ecuador / Evaluation of the microbiological quality of natural processed products for medicinal use marketed in Quito, Ecuador

RESUMEN Objetivos: Determinar la calidad microbiológica de una muestra de productos naturales procesados de uso medicinal de libre comercio en Quito, Ecuador. Materiales y métodos: 83 productos se sometieron a recuentos de microorganismos aerobios, mohos y levaduras por técnicas convencionales estandarizadas, de acuerdo a la Farmacopea de los Estados Unidos (USP, por sus siglas en inglés). Se identificaron los microorganismos presentes y se determinó su sensibilidad antimicrobiana usando el método de difusión en agar. Resultados: El 17,0% de los jarabes, el 27,0% de los productos tópicos y el 43,0% de los sólidos orales excedieron los límites especificados para el recuento total de microorganismos aerobios, mientras que el 33,0% de los jarabes, el 7,0% de los productos tópicos y el 36,0% de los sólidos orales excedieron el límite para mohos y levaduras. Los productos de uso ocular no pasaron la prueba de esterilidad. El género bacteriano más frecuentemente aislado fue Bacillus, seguido por Escherichia coli, Klebsiella y Enterobacter. Salmonella ni Staphylococcus aureus se encontraron en ningún producto, pero microorganismos potencialmente patógenos como Pseudomonas se aislaron en el 40,0% de los colirios. Enterobacter y Escherichia coli mostraron resistencia a múltiples compuestos y Pseudomonas no fue resistente a ningún antibiótico. Conclusiones: La calidad microbiológica de los productos examinados no fue adecuada. Se aislaron microorganismos potencialmente patógenos y resistentes a antibióticos. Estos productos podrían no ser aptos para su distribución y consumo, aun cuando muchos de ellos cuenten con registro sanitario. El control y regulación por los entes responsables es indispensable.

ABSTRACT Objectives: To determine the microbiological quality of samples from processed natural products used for medicinal purposes and marketed in Quito, Ecuador. Materials and methods: Aerobic microorganisms, molds and yeasts were counted by conventional standardized techniques, according to the United States Pharmacopoeia (USP), in samples from 83 products. The microorganisms found were identified and their antimicrobial sensitivity was determined using the agar diffusion method. Results: The total aerobic microorganism count exceeded the specified limits in 17.0% of syrups, 27.0% of topical products and 43.0% of oral solids; the molds and yeasts count exceeded the limit in 33.0% of syrups, 7.0% of topical products and 36.0% of oral solids. Products for eye use did not pass the sterility test. The most frequently isolated bacterial genus was Bacillus, followed by Escherichia coli, Klebsiella and Enterobacter. Salmonella and Staphylococcus aureus were not found in any product, but potentially pathogenic microorganisms such as Pseudomonas were isolated in 40.0% of the eye drops. Enterobacter and Escherichia coli showed resistance to multiple compounds and Pseudomonas was not resistant to any antibiotic. Conclusions: The microbiological quality of the products examined was not adequate. Potentially pathogenic and antibiotic resistant microorganisms were isolated from the samples. These products may not be suitable for distribution and consumption, even though many of them have sanitary registration. Control and regulation by the corresponding authorities is essential.

Biomimetic cellular vectors for enhancing drug delivery to the lungs.

Despite recent advances in drug delivery, the targeted treatment of unhealthy cells or tissues continues to remain a priority. In cancer (much like other pathologies), delivery vectors are designed to exploit physical and biological features of unhealthy tissues that are not always homogenous across the disease. In some cases, shifting the target from unhealthy tissues to the whole organ can represent an advantage. Specifically, the natural organ-specific retention of nanotherapeutics following intravenous administration as seen in the lung, liver, and spleen can be strategically exploited to enhance drug delivery. Herein, we outline the development of a cell-based delivery system using macrophages as a delivery vehicle. When loaded with a chemotherapeutic payload (i.e., doxorubicin), these cellular vectors (CELVEC) were shown to provide continued release within the lung. This study provides proof-of-concept evidence of an alternative class of biomimetic delivery vectors that capitalize on cell size to provide therapeutic advantages for pulmonary treatments.

Rapamycin-Loaded Biomimetic Nanoparticles Reverse Vascular Inflammation.

RATIONALE: Through localized delivery of rapamycin via a biomimetic drug delivery system, it is possible to reduce vascular inflammation and thus the progression of vascular disease. OBJECTIVE: Use biomimetic nanoparticles to deliver rapamycin to the vessel wall to reduce inflammation in an in vivo model of atherosclerosis after a short dosing schedule. METHODS AND RESULTS: Biomimetic nanoparticles (leukosomes) were synthesized using membrane proteins purified from activated J774 macrophages. Rapamycin-loaded nanoparticles were characterized using dynamic light scattering and were found to have a diameter of 108±2.3 nm, a surface charge of -15.4±14.4 mV, and a polydispersity index of 0.11 +/ 0.2. For in vivo studies, ApoE-/- mice were fed a high-fat diet for 12 weeks. Mice were injected with either PBS, free rapamycin (5 mg/kg), or rapamycin-loaded leukosomes (Leuko-Rapa; 5 mg/kg) once daily for 7 days. In mice treated with Leuko-Rapa, flow cytometry of disaggregated aortic tissue revealed fewer proliferating macrophages in the aorta (15.6±9.79 %) compared with untreated mice (30.2±13.34 %) and rapamycin alone (26.8±9.87 %). Decreased macrophage proliferation correlated with decreased levels of MCP (monocyte chemoattractant protein)-1 and IL (interleukin)-b1 in mice treated with Leuko-Rapa. Furthermore, Leuko-Rapa-treated mice also displayed significantly decreased MMP (matrix metalloproteinases) activity in the aorta (mean difference 2554±363.9, P=9.95122×10-6). No significant changes in metabolic or inflammation markers observed in liver metabolic assays. Histological analysis showed improvements in lung morphology, with no alterations in heart, spleen, lung, or liver in Leuko-Rapa-treated mice. CONCLUSIONS: We showed that our biomimetic nanoparticles showed a decrease in proliferating macrophage population that was accompanied by the reduction of key proinflammatory cytokines and changes in plaque morphology. This proof-of-concept showed that our platform was capable of suppressing macrophage proliferation within the aorta after a short dosing schedule (7 days) and with a favorable toxicity profile. This treatment could be a promising intervention for the acute stabilization of late-stage plaques.

Leukocyte-mimicking nanovesicles for effective doxorubicin delivery to treat breast cancer and melanoma.

In the last decades, several approaches were developed to design drug delivery systems to address the multiple biological barriers encountered after administration while safely delivering a payload. In this scenario, bio-inspired and bio-mimetic approaches have emerged as promising solutions to evade the mononuclear phagocytic system while simultaneously negotiating the sequential transport across the various biological barriers. Leukocytes freely circulate in the bloodstream and selectively target the inflamed vasculature in response to injury, infection, and cancer. Recently we have shown the use of biomimetic nanovesicles, called leukosomes, which combine both the physical and biological properties of liposomes and leukocytes, respectively, to selectively deliver drugs to the inflamed vasculature. Here we report the use of leukosomes to target and deliver doxorubicin, a model chemotherapeutic, to tumors in syngeneic murine models of breast cancer and melanoma. Exploiting the inflammatory pathway responsible for recruiting immune cells to the site of injury, leukosomes exhibited increased targeting of cancer vasculature and stroma. Furthermore, delivery of doxorubicin with leukosomes enabled significant tumor growth inhibition compared with free doxorubicin in both breast and melanoma tumors. This study demonstrates the promise of using biomimetic nanovesicles for effective cancer management in solid tumors.

Macrophage-derived nanovesicles exert intrinsic anti-inflammatory properties and prolong survival in sepsis through a direct interaction with macrophages.

Despite numerous advances in medical treatment, sepsis remains one of the leading causes of death worldwide. Sepsis is characterized by the involvement of all organs and tissues as a consequence of blood poisoning, resulting in organ failure and eventually death. Effective treatment remains an unmet need and novel approaches are urgently needed. The growing evidence of clinical and biological heterogeneity of sepsis suggests precision medicine as a possible key for achieving therapeutic breakthroughs. In this scenario, biomimetic nanomedicine represents a promising avenue for the treatment of inflammatory diseases, including sepsis. We investigated the role of macrophage-derived biomimetic nanoparticles, namely leukosomes, in a lipopolysaccharide-induced murine model of sepsis. We observed that treatment with leukosomes was associated with significantly prolonged survival. In vitro studies elucidated the potential mechanism of action of these biomimetic vesicles. The direct treatment of endothelial cells (ECs) with leukosomes did not alter the gene expression profile of EC-associated cell adhesion molecules. In contrast, the interaction of leukosomes with macrophages induced a decrease of pro-inflammatory genes (IL-6, IL-1b, and TNF-α), an increase of anti-inflammatory ones (IL-10 and TGF-ß), and indirectly an anti-inflammatory response on ECs. Taken together, these results showed the ability of leukosomes to regulate the inflammatory response in target cells, acting as a bioactive nanotherapeutic.

Trends towards Biomimicry in Theranostics.

Over the years, imaging and therapeutic modalities have seen considerable progress as a result of advances in nanotechnology. Theranostics, or the marrying of diagnostics and therapy, has increasingly been employing nano-based approaches to treat cancer. While first-generation nanoparticles offered considerable promise in the imaging and treatment of cancer, toxicity and non-specific distribution hindered their true potential. More recently, multistage nanovectors have been strategically designed to shield and carry a payload to its intended site. However, detection by the immune system and sequestration by filtration organs (i.e., liver and spleen) remains a major obstacle. In an effort to circumvent these biological barriers, recent trends have taken inspiration from biology. These bioinspired approaches often involve the use of biologically-derived cellular components in the design and fabrication of biomimetic nanoparticles. In this review, we provide insight into early nanoparticles and how they have steadily evolved to include bioinspired approaches to increase their theranostic potential.

Biomimetic nanoparticles with enhanced affinity towards activated endothelium as versatile tools for theranostic drug delivery.

Activation of the vascular endothelium is characterized by increased expression of vascular adhesion molecules and chemokines. This activation occurs early in the progression of several diseases and triggers the recruitment of leukocytes. Inspired by the tropism of leukocytes, we investigated leukocyte-based biomimetic nanoparticles (i.e., leukosomes) as a novel theranostic platform for inflammatory diseases. Methods: Leukosomes were assembled by combining phospholipids and membrane proteins from leukocytes. For imaging applications, phospholipids modified with rhodamine and gadolinium were used. Leukosomes incubated with antibodies blocking lymphocyte function-associated antigen 1 (LFA-1) and CD45 were administered to explore their roles in targeting inflammation. In addition, relaxometric assessment of NPs was evaluated. Results: Liposomes and leukosomes were both spherical in shape with sizes ranging from 140-170 nm. Both NPs successfully integrated 8 and 13 µg of rhodamine and gadolinium, respectively, and demonstrated less than 4% variation in physicochemical features. Leukosomes demonstrated a 16-fold increase in breast tumor accumulation relative to liposomes. Furthermore, quantification of leukosomes in tumor vessels demonstrated a 4.5-fold increase in vessel lumens and a 14-fold increase in vessel walls. Investigating the targeting mechanism of action revealed that blockage of LFA-1 on leukosomes resulted in a 95% decrease in tumor accumulation. Whereas blockage of CD45 yielded a 60% decrease in targeting and significant increases in liver and spleen accumulation. In addition, when administered in mice with atherosclerotic plaques, leukosomes exhibited a 4-fold increase in the targeting of inflammatory vascular lesions. Lastly, relaxometric assessment of NPs demonstrated that the incorporation of membrane proteins into leukosomes did not impact the r1 and r2 relaxivities of the NPs, demonstrating 6 and 30 mM-1s-1, respectively. Conclusion: Our study demonstrates the ability of leukosomes to target activated vasculature and exhibit superior accumulation in tumors and vascular lesions. The versatility of the phospholipid backbone within leukosomes permits the incorporation of various contrast agents. Furthermore, leukosomes can potentially be loaded with therapeutics possessing diverse physical properties and thus warrant further investigation toward the development of powerful theranostic agents.

Hyaluronic acid coatings as a simple and efficient approach to improve MSC homing toward the site of inflammation.

A major challenge in regenerative medicine is to improve therapeutic cells' delivery and targeting using an efficient and simple protocol. Mesenchymal stem cells (MSC) are currently employed for the treatment of inflammatory-based diseases, due to their powerful immunosoppressive potential. Here we report a simple and versatile method to transiently overexpress the hyaluronic acid (HA) receptor, CD44, on MSC membranes, to improve their homing potential towards an inflammatory site without affecting their behavior. The effect of HA-coatings on murine MSC was functionally determined both, in vitro and in vivo as a consequence of the transient CD44 overexpression induced by HA. Data obtained from the in vitro migration assay demonstrated a two-fold increase in the migratory potential of HA-treated MSC compared to untreated cells. In an LPS-induced inflamed ear murine model, HA-treated MSC demonstrated a significantly higher inflammatory targeting as observed at 72 hrs as compared to untreated cells. This increased accumulation for HA-treated MSC yielded a substantial reduction in inflammation as demonstrated by the decrease in the expression of pro-inflammatory markers and by the induction of a pro-regenerative environment.

Chlorin e6 Functionalized Theranostic Multistage Nanovectors Transported by Stem Cells for Effective Photodynamic Therapy.

Approaches to achieve site-specific and targeted delivery that provide an effective solution to reduce adverse, off target side effects are urgently needed for cancer therapy. Here, we utilized a Trojan-horse-like strategy to carry photosensitizer Chlorin e6 conjugated porous silicon multistage nanovectors with tumor homing mesenchymal stem cells for targeted photodynamic therapy and diagnosis. The inherent versatility of multistage nanovectors permitted the conjugation of photosensitizers to enable precise cell death induction (60%) upon photodynamic therapy, while simultaneously retaining the loading capacity to load various payloads, such as antitumor drugs and diagnostic nanoparticles. Furthermore, the mesenchymal stem cells that internalized the multistage nanovectors conserved their proliferation patterns and in vitro affinity to migrate and infiltrate breast cancer cells. In vivo administration of the mesenchymal stem cells carrying photosensitizer-conjugated multistage nanovectors in mice bearing a primary breast tumor confirmed their tropism toward cancer sites exhibiting similar targeting kinetics to control cells. In addition, this approach yielded in a > 70% decrease in local tumor cell viability after in vivo photodynamic therapy. In summary, these results show the proof-of-concept of how photosensitizer conjugated multistage nanovectors transported by stem cells can target tumors and be used for effective site-specific cancer therapy while potentially minimizing potential negative side effects.

Biomimetic Concealing of PLGA Microspheres in a 3D Scaffold to Prevent Macrophage Uptake.

Scaffolds functionalized with delivery systems for the release of growth factors is a robust strategy to enhance tissue regeneration. However, after implantation, macrophages infiltrate the scaffold, eventually initiating the degradation and clearance of the delivery systems. Herein, it is hypothesized that fully embedding the poly(d,l-lactide-co-glycolide acid) microspheres (MS) in a highly structured collagen-based scaffold (concealing) can prevent their detection, preserving the integrity of the payload. Confocal laser microscopy reveals that non-embedded MS are easily internalized; when concealed, J774 and bone marrow-derived macrophages (BMDM) cannot detect them. This is further demonstrated by flow cytometry, as a tenfold decrease is found in the number of MS engulfed by the cells, suggesting that collagen can cloak the MS. This correlates with the amount of nitric oxide and tumor necrosis factor-α produced by J774 and BMDM in response to the concealed MS, comparable to that found for non-functionalized collagen scaffolds. Finally, the release kinetics of a reporter protein is preserved in the presence of macrophages, only when MS are concealed. The data provide detailed strategies for fabricating three dimensional (3D) biomimetic scaffolds able to conceal delivery systems and preserve the therapeutic molecules for release.

Multistage vector delivery of sulindac and silymarin for prevention of colon cancer.

Familial adenomatous polyposis (FAP) is an inherited condition secondary to germline mutations in the APC gene, thus resulting in the formation of hundreds of colonic adenomas that eventually progress into colon cancer. Surgical removal of the colon remains the only treatment option to avoid malignancy, as long-term exposure to chemopreventive agents such as sulindac (a non-steroidal anti-inflammatory drug) and silymarin (phytoestrogen) is not feasible. Here, we have developed a multistage silicon-based drug delivery platform for sulindac and silymarin that preferentially interacts with colon cancer cells as opposed to normal intestinal mucosa. Preferential binding and internalization of these drugs into colon cancer cells was obtained using a targeting strategy against the protein meprin A, which we demonstrate is overexpressed in human colon cancer cells and in the small intestine of Apc(Min/+) mice. We propose that this delivery system could potentially be used to reduce drug-induced side effects in FAP patients, thus enabling long-term prevention of adenoma formation.

Multistage Nanovectors Enhance the Delivery of Free and Encapsulated Drugs.

Nanoparticles have considerable potential for cancer imaging and therapy due to their small size and prolonged circulation. However, biological barriers can impede the delivery of a sufficient dose of a drug to the target site, thereby also resulting in the accumulation of toxic compounds within healthy tissues, and systemic toxicity. Multistage nanovectors (MSV) preferentially accumulate on inflamed endothelium, and can thus serve as carriers for drugs and nanoparticles. Herein, we describe the loading of free (i.e., melittin) and nano-encapsulated (i.e., doxorubicin-loaded micelles) drugs into MSV, and report the impact of surface charge and pore size on drug loading. For both drug formulations, negatively charged MSV (i.e., oxidized) with larger pores were shown to retain higher concentrations of payloads compared to positively charged (i.e., APTES-modified) MSV with small pores. Treatment of human umbilical vein endothelial cells (HUVEC) with melittin-loaded MSV (MEL@MSV) resulted in an 80% reduction in cell viability after 3 days. Furthermore, MEL@MSV conjugated with antivascular endothelial growth factor receptor 2 (VEGFR2) antibodies displayed preferential targeting and delivery of MEL to activated HUVEC expressing VEGFR2. Treatment of HUVEC and MCF7 cells with doxorubicin-loaded micelles (DOXNP@MSV) resulted in a 23% and 47% reduction in cell viability, respectively. Taken together, these results demonstrate increased loading of a payload in oxidized, large pore MSV, and effective delivery of free and nano-encapsulated drugs to endothelial and cancer cells.

The effect of multistage nanovector targeting of VEGFR2 positive tumor endothelia on cell adhesion and local payload accumulation.

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 EPR, relying on particle geometry and surface adhesion. By studying endothelial cells overexpressing vascular endothelial growth factor receptor-2 (VEGFR2), we developed MSV able to preferentially target VEGFR2 expressing tumor-associated vessels. Static and dynamic targeting revealed that MSV conjugated with anti-VEGFR2 antibodies displayed greater than a 4-fold increase in targeting efficiency towards VEGFR2 expressing cells while exhibiting minimal adherence to control cells. Additionally, VEGFR2 conjugation bestowed MSV with a significant increase in breast tumor targeting and in the delivery of a model payload while decreasing their accumulation in the liver. Surface functionalization with an anti-VEGFR2 antibody provided enhanced affinity towards the tumor vascular endothelium, which promoted enhanced adhesion and tumoritropic accumulation of a reporter molecule released by the MSV.

Bromelain surface modification increases the diffusion of silica nanoparticles in the tumor extracellular matrix.

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 effect of tumor vasculature, typical nanotherapeutics are unable to reach the nonvascularized and anoxic regions deep within cancer parenchyma. Here, we developed a simple method to provide mesoporous silica nanoparticles (MSN) with a proteolytic surface. To this extent, we chose to conjugate MSN to Bromelain (Br-MSN), a crude enzymatic complex, purified from pineapple stems, that belongs to the peptidase papain family. This surface modification increased particle uptake in endothelial, macrophage, and cancer cell lines with minimal impact on cellular viability. Most importantly Br-MSN showed an increased ability to digest and diffuse in tumor ECM in vitro and in vivo.

Exome sequencing identifies RDH12 compound heterozygous mutations in a family with severe retinitis pigmentosa.

OBJECTIVE: Retinitis pigmentosa (RP) is the most prevalent type of inherited retinal degeneration and one of the commonest causes of genetically determined visual dysfunction worldwide. To date, approximately 35 genes have been associated with nonsyndromic autosomal recessive RP (arRP), however the small contribution of each gene to the total prevalence of arRP and the lack of a clear genotype-phenotype correlation complicate the genetic analysis in affected patients. Next generation sequencing technologies are powerful and cost-effective methods for detecting causative mutations in both sporadic and familial RP cases. METHODS: A Mexican family with 5 members affected from arRP was studied. All patients underwent a complete ophthalmologic examination. Molecular methods included genome-wide SNP homozygosity mapping, exome sequencing analysis, and Sanger-sequencing confirmation of causal mutations. RESULTS: No regions of shared homozygosity among affected subjects were identified. Exome sequencing in a single patient allowed the detection of two missense mutations in the RDH12 gene: a c.446T>C transition predicting a novel p.L149P substitution, and a c.295C>A transversion predicting a previously reported p.L99I replacement. Sanger sequencing confirmed that all affected subjects carried both RDH12 mutations. CONCLUSIONS: This study adds to the molecular spectrum of RDH12-related retinopathy and offers an additional example of the power of exome sequencing in the diagnosis of recessively inherited retinal degenerations.