Covalent and Noncovalent Loading of Doxorubicin by Folic Acid-Carbon Dot Nanoparticles for Cancer Theranostics.

With special properties such as excellent fluoresce features, low toxicity, good biocompatibility, permeability, and easy clearance from the body, carbon dot (CD)-based nanoparticles (NPs) have the potential to deliver drugs and use in vivo diagnostics through molecular imaging. In this work, folic acid-CD (FA-CD) NPs were prepared to deliver doxorubicin (Dox) covalently and noncovalently as cancer theranostics. FA was conjugated to the surface of CDs for targeting cancer cells with overexpressing folate receptors. CDs prepared with various amounts of precursors lead to their associated NPs with different photoluminescence properties and drug release profiles. The loading of Dox and its releasing data depends on the linkage of drug Dox to FA-CD and CD composition. All NPs were characterized by UV-vis, Fourier transform infrared spectroscopy, and dynamic light scattering. The noncovalent FA-CD-Dox NPs were preferred with a simple preparation process, excellent photoluminescence, and in vitro drug release properties. The noncovalent FA-CD-Dox showed the best efficacy against MDA-MB-231 compared to the CD-Dox and covalent FA-CD-Dox.

Comparison of pharmacists' scoring of fall risk to other fall risk assessments.

OBJECTIVES: Given their professional education and participation within the health care system, pharmacists are ideal candidates to assess drug-associated fall risk for patients. The purpose of this investigation was to determine whether pharmacists can quantitatively differentiate individuals who reported falling within the previous year (fallers) from those who do not (nonfallers), and to compare the pharmacists' evaluation with 2 recently published fall risk assessments. DESIGN: Cross-sectional design of pharmacists' assessments of fall risk. SETTING AND PARTICIPANTS: This is a cross-sectional study where 6 licensed pharmacists evaluated patient records from Wave 1 of the National Social Life, Health and Aging Project dataset using generic drug list (drug counts), age, and body mass index to generate a Pharmacist Risk Score (PRS) based on these variables. Pharmacists were allowed to use drug information resources and were provided with a simple 5-point scale to assist them in scoring patients. OUTCOME MEASURES: The main outcome measure of this study was a comparison of the following fall risk assessments (PRS, drug counts, Medication-Based Index of Physical Function, Quantitative Drug Index, and Timed Up and Go [TUG]) capacity to differentiate fallers from nonfallers. RESULTS: Each fall risk assessment was highly correlated (P < 0.001) with the number of reported falls. Drug-associated fall risk assessments were highly correlated (P < 0.001) with each other, but not with TUG. Each fall risk assessment differentiated fallers from nonfallers based on logistic regression (P ≤ 0.001). Receiver operating characteristic (ROC) curve analysis was significant (P ≤ 0.002) for each assessment. The comparison of ROC area under the curve for the fall risk assessments found no significant difference between the PRS and other assessments. CONCLUSION: Fall risk assessment by pharmacists was comparable with other fall risk assessments in distinguishing fallers from nonfallers.

Intracellular sequestration of HER2 via targeted subcellular peptide delivery.

The use of peptides in drug development has been hampered by their poor pharmaceutical properties, most notably their inability to reliably permeate biological membranes and lack of targeting. To overcome these disadvantages, the AMino acid Intracellular Delivery SysTem (AMIDST) was developed. This modular peptide-based delivery system confers cellular permeability and organelle-specific targeting for therapeutic peptides. As demonstrated in this study, the delivery of a HER2-binding peptide to the secretory organelles of breast cancer cells resulted in intracellular sequestration, a reduction in downstream signalling, and reduced viability compared to the delivery of a control peptide. Given its modular design and ease of production, AMIDST has the potential to enhance the use of peptides as therapeutic agents.

Influences of Age, Obesity, and Adverse Drug Effects on Balance and Mobility Testing Scores in Ambulatory Older Adults.

BACKGROUND AND PURPOSE: The adverse effects of drugs may influence results on tests of mobility and balance, but the drug-specific impact is not identified when using these tests. We propose that a quantitative drug index (QDI) will assist in assessing fall risk based on these tests, when combined with other fall risk variables. METHODS: Fifty-seven community-dwelling older adults who could walk independently on a treadmill and had Mini-Mental State Examination (MMSE) scores equal to or greater than 24 participated. Mobility and balance outcome measures included the Balance Evaluation Systems Test (BESTest), Berg Balance Scale (BBS), Timed Up and Go (TUG) and cognitive dual task TUG (TUGc). Fall history, current drug list, and Activity-Specific Balance Confidence (ABC) scale scores were also collected. Body mass index (BMI) was calculated. The QDI was derived from the drug list for each individual, and based on fall-related drug adverse effects. Multiple linear regression analyses were conducted using age, BMI, and QDI as predictor variables for determining mobility and balance test scores, and ABC scale scores. Subsequently, participants were divided into (QDI = 0) low-impact drug group (LIDG) and (QDI > 0) high-impact drug group (HIDG) for Mann-Whitney 2-group comparisons. RESULTS: Age, BMI, and QDI were all significant (P < .001) independent variables in multiple regression analyses for mobility and balance test scores, but not for the ABC scale. Separately, the 2 group comparisons for the BESTest, BBS, TUG, and TUGc demonstrated that HIDG scored significantly (P < .05) worse on these tests compared with the LIDG. Drug counts were also significantly higher for the HIDG than for the LIDG. In contrast, age, BMI, MMSE, and reported falls in the last 12 months were not significantly different between groups. CONCLUSION: Age, BMI, and QDI-all contributed independently to the mobility and balance test scores examined, and may provide health care professionals a screening tool to determine whether additional mobility and balance testing is required. In addition, the QDI is a more precise marker of adverse effects of drugs compared with drug counts, as the latter does not quantitate the influence of drugs on physiologic function.

Development and evaluation of the medication-based index of physical function (MedIP).

Background: the development of an objective and comprehensive drug-based index of physical function for older adults has the potential to more accurately predict fall risk. Design: the index was developed using 862 adults (ages 57-85) from the National Social Life, Health, and Aging Project (NSHAP) Wave 1 study. The index was evaluated in 70 adults (ages 51-88) from a rehabilitation study of dizziness and balance. Methods: the prevalence among 601 drugs for 1,694 side effects was used with fall history to determine the magnitude of each side effect's contribution towards physical function. This information was used to calculate a Medication-based Index of Physical function (MedIP) score for each individual based on his or her medication profile. The MedIP was compared to the timed up and go (TUG) test as well as drug counts using receiver operating characteristic (ROC) analysis. The associations between various indices of physical function and MedIP were calculated. Results: within the NSHAP data set, the MedIP was better than drug counts or TUG at predicting falls based on ROC analysis. Using scores above and below the cutpoint, the MedIP was a significant predictor of falls (OR = 2.61 [95% CI 1.83, 3.64]; P < 0.001). Using an external data set, it was shown that the MedIP was significantly correlated with fall number (P = 0.044), composite physical function (P = 0.026) and preferred gait speed (P = 0.043). Conclusion: the MedIP has the potential to become a useful tool in the healthcare and fall prevention of older individuals.

Using scientific inquiry to increase knowledge of vaccine theory and infectious diseases.

BACKGROUND: The aim of this study was to design and evaluate a laboratory activity based on scientific inquiry to educate first-year pharmacy students in the U.S. about vaccination theory and the attributes of common pathogens. METHODS: The laboratory activity had two principal sections. The first consisted of an interactive game during which students rolled a die to determine outcomes based on a set of pre-determined criteria. In the second section, students generated and tested hypotheses about vaccine theory using a computer simulation that modeled disease transmission within a large population. In each section students were asked to evaluate epidemiological data and make inferences pertinent to vaccination effectiveness. RESULTS: Mean scores on a knowledge-based assessment given immediately before and immediately after the activity increased from 46% to 71%. DISCUSSION: A laboratory activity designed to stimulate scientific inquiry within pharmacy students enabled them to increase their knowledge of common vaccines and infectious diseases.

Liposomal Coencapsulation of Doxorubicin with Listeriolysin O Increases Potency via Subcellular Targeting.

Liposomal doxorubicin is a clinically important drug formulation indicated for the treatment of several different forms of cancer. For doxorubicin to exert a therapeutic effect, it must gain access to the nucleus. However, a large proportion of the liposomal doxorubicin dose fails to work because it is sequestered within endolysosomal organelles following endocytosis of the liposomes due to the phenomenon of ion trapping. Listeriolysin O (LLO) is a pore-forming protein that can provide a mechanism for endosomal escape. The present study demonstrates that liposomal coencapsulation of doxorubicin with LLO enables a significantly larger percentage of the dose to colocalize with the nucleus compared to liposomes containing doxorubicin alone. The change in intracellular distribution resulted in a significantly more potent formulation of liposomal doxorubicin as demonstrated in both the ovarian carcinoma cell line A2780 and its doxorubicin-resistant derivative A2780ADR.

Synthesis and characterization of valyloxy methoxy luciferin for the detection of valacyclovirase and peptide transporter.

An amino acid ester derivative of luciferin (valoluc) was synthesized to mimic the transport and activation of valacyclovir. This molecule was characterized in vitro for specificity and enzymatic constants, and then assayed in two different, physiologically-relevant conditions. It was demonstrated that valoluc activation is sensitive to the same cellular factors as valacyclovir and thus has the potential to elucidate the dynamics of amino acid ester prodrug therapies in a functional, high-throughput manner.

Mutants of listeriolysin O for enhanced liposomal delivery of macromolecules.

Delivery of macromolecules into the cytosolic space of eukaryotic cells is a pressing challenge in biopharmaceutics. Macromolecules are often encapsulated into liposomes for protection and improved distribution, but the their size often induces endocytosis of the vehicle at the target site, leading to degradation of the cargo. Listeriolysin O is a key virulence factor of Listeria monocytogenes that forms pores in the endosomal membrane, ultimately allowing the bacterium to escape into the cytosol. This function of LLO has been used to improve cytosolic delivery of liposomally encapsulated macromolecules in a number of instances, but its innate toxicity and immunogenicity have prevented it from achieving widespread acceptance. Through site-directed mutagenesis, this study establishes a mutant of LLO (C484S) with enhanced activity, allowing for a reduction in the amount of LLO used for future applications in liposomal drug delivery.

Specificity of a prodrug-activating enzyme hVACVase: the leaving group effect.

Human valacyclovirase (hVACVase) is a prodrug-activating enzyme for amino acid prodrugs including the antiviral drugs valacyclovir and valganciclovir. In hVACVase-catalyzed reactions, the leaving group of the substrate corresponds to the drug moiety of the prodrug, making the leaving group effect essential for the rational design of new prodrugs targeting hVACVase activation. In this study, a series of valine esters, phenylalanine esters, and a valine amide were characterized for the effect of the leaving group on the efficiency of hVACVase-mediated prodrug activation. Except for phenylalanine methyl and ethyl esters, all of the ester substrates exhibited a relatively high specificity constant (k(cat)/K(m)), ranging from 850 to 9490 mM(-1)·s(-1). The valine amide Val-3-APG exhibited significantly higher K(m) and lower k(cat) values compared to the corresponding ester Val-3-HPG, indicating poor specificity for hVACVase. In conclusion, the substrate leaving group has been shown to affect both binding and specific activity of hVACVase-catalyzed activation. It is proposed that hVACVase is an ideal target for α-amino acid ester prodrugs with relatively labile leaving groups while it is relatively inactivate toward amide prodrugs.

A generalizable strategy for imaging pre-mRNA levels in living subjects using spliceosome-mediated RNA trans-splicing.

UNLABELLED: Molecular imaging of gene expression is currently hindered by the lack of a generalizable platform for probe design. For any gene of interest, a probe that targets protein levels must often be generated empirically. Targeting gene expression at the level of mRNA, however, would allow probes to be built on the basis of sequence information alone. Presented here is a class of generalizable probes that can image pre-mRNA in a sequence-specific manner, using signal amplification and a facile method of delivery. METHODS: Pre-trans-splicing molecules (PTMs) were engineered to capitalize on the phenomenon of spliceosome-mediated RNA trans-splicing. Using a modular binding domain that confers specificity by base-pair complementarity to the target pre-mRNA, PTMs were designed to target a chimeric target mini gene and trans-splice the Renilla luciferase gene onto the end of the target. PTMs and target genes were transfected in cell culture and assessed by luciferase assay, reverse-transcriptase polymerase chain reaction, Western blot, and rapid analysis of 5' cDNA ends. PTMs and target genes were also assessed in vivo by hydrodynamic delivery in mice. RESULTS: Efficiency and specificity of the trans-splicing reaction were found to vary depending on the binding domain length and structure. Specific trans-splicing was observed in living animals (P = 0.0862, Kruskal-Wallis test). CONCLUSION: Described here is a model system used to demonstrate the feasibility of spliceosome-mediated RNA trans-splicing for imaging gene expression at the level of pre-mRNA using optical imaging techniques in living animals. The experiments reported here show proof of principle for a generalizable imaging probe against RNA that can amplify signal on detection and be delivered using existing gene delivery methodology.

BRET-based method for detection of specific RNA species.

RNA detection and quantitation is a common necessity in modern molecular biology research. Most methods, however, are complex and/or time-intensive. Presented here is a BRET (bioluminescene resonance energy transfer)-based method that can accomplish the task of RNA identification quickly and easily. By conjugating BRET enzymes to two different oligonucleotides that are complementary to the same target sequence, probes were developed that could detect RNA using a solution-based assay. This assay was optimized for spacer length between the binding sites (found to be 10 nucleotides), and sensitivity was determined to be 1 microg for a specific species of RNA within a mixed population. Specificity of the assay was assessed using in vitro transcribed cRNA and found to be statistically siginificant ( p = 3.11 x 10 (-6), ANOVA, multiple range test). This assay represents a possibility for a less technically demanding, streamlined alternative to canonical RNA assays.