Serum Bioavailability Research Articles

Decoupling Fluorous Protein Coatings Yield Heat-Stable and Intrinsically Sterile Bioformulations.

Thermal inactivation is a major bottleneck to the scalable production, storage, and transportation of protein-based reagents and therapies. Failures in temperature control both compromise protein bioactivity and increase the risk of microorganismal contamination. Herein, we report the rational design of fluorochemical additives that promiscuously bind to and coat the surfaces of proteins to enable their stable dispersion within fluorous solvents. By replacing traditional aqueous liquids with fluorinated media, this strategy conformationally rigidifies proteins to preserve their structure and function at extreme temperatures (≥90 °C). We show that fluorous protein formulations resist contamination by bacterial, fungal, and viral pathogens, which require aqueous environments for survival, and display equivalent serum bioavailability to standard saline samples in animal models. Importantly, by designing dispersants that decouple from the protein surface in physiologic solutions, we deliver a fluorochemical formulation that does not alter the pharmacologic function or safety profile of the functionalized protein in vivo. As a result, this nonaqueous protein storage paradigm is poised to open technological opportunities in the design of shelf-stable protein reagents and biopharmaceuticals.

Abstract 7306: Licochalcone A is an excellent candidate for preventing luminal and non-luminal breast cancers

Abstract Breast cancer (BC) risk reducing drugs have minimal impact due to their adverse effects and low acceptance by risk-eligible women. Further, they are ineffective against hormone receptor negative (HR-) BC. Novel agents with reduced toxicity and sufficient efficacy that extends beyond HR+ BC are needed. We showed previously that licochalcone A (LicA) from licorice has antioxidant/anti-inflammatory effects, inhibits aromatase, and blocks estrogen genotoxic metabolism. We hypothesize that LicA prevents HR+ and HR- BC through reprogramming metabolism and antioxidant pathways. We prepared microstructures from the fresh tissue of contralateral unaffected breast of 6 postmenopausal women with unilateral BC. After exposing them to DMSO (control) or LicA (5 µM), we performed total RNA sequencing followed by differential gene expression, pathway identification, and metabolism flux analyses. The NanoString metabolism panel was employed in 6 additional subjects. We performed live cell imaging to monitor proliferation of HR- and HR+ pre-malignant and malignant, as well as BRCA mutated cells. Xenograft models of HR+ and HR- tumors were established in female nude mice followed by 28-day treatment with vehicle or LicA (80 mg/kg.day, s.c.) and monitoring the tumor growth. Using LC-MS/MS we measured LicA in the blood and various tissues of intact BALB/c female mice receiving oral LicA (100 mg/kg) and assessed PK using Phoenix Platform. We observed significant (combined enrichment scores > 4 and FDR < 0.05) upregulation of antioxidant genes (up to 8-fold), consistent with upregulation of NRF2 and the thioredoxin system. This was accompanied by significant downregulation of RELA- and NF-kB1-dependent inflammatory pathways. In addition, we observed decreased expression of PI3K-AKT genes and the pro-adipogenic transcription factors SREBF1 and SREBF2, which may explain the downregulation (4 to 32-fold) of cholesterol biosynthesis, transport, and lipid metabolism genes. Metabolism studies confirmed these data and demonstrated a robust increase in the pentose phosphate shunt and NAD(P)H generation without enhancing ribose 5 phosphate formation, suggesting an antioxidant and antiproliferative environment. LicA also suppressed proliferation of pre-malignant and malignant cells, with sustained effects on aggressive cell lines at doses <10 µM. It reduced tumor growth in luminal (P = 0.008) and triple negative (P = 0.001) xenograft models. Oral bioavailability in serum and breast was in the low micromolar range and was sufficient to show efficacy.Our data suggest that LicA is an excellent candidate for both HR+ and HR- BC prevention by reprogramming metabolism and antioxidant pathways leading to decreased proliferation. Our next study will test an optimized oral formulation of LicA in intraductal models of HR+ and HR- precancer lesions in immunocompetent mice to further establish its preventive efficacy. Citation Format: Atieh Hajirahimkhan, Elizabeth T. Bartom, Sriram Chandrasekaran, Ruohui Chen, Jeremy J. Johnson, Susan E. Clare, Seema A. Khan. Licochalcone A is an excellent candidate for preventing luminal and non-luminal breast cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7306.

The Effect of a Diet Supplemented with Organic Minerals and l-Carnitine on Egg Production and Chemical Composition and on Some Blood Traits of Pheasant Hens (Phasianus colchicus)

The study aimed to determine the effect of replacing 75% of inorganic calcium, iron, zinc, and copper salts with organic forms (glycine chelates of these elements) with or without the addition of l-carnitine on some reproductive traits and the blood lipid and mineral profile, as well as mineral and fatty acid profile of pheasant egg yolk. The study was performed on three groups of pheasant hens using glycine chelates with calcitriol (group II) or analogical treatment with the addition of l-carnitine at the level of 100 mg/kg of feed (group III) instead of Ca, Fe, Cu, and Zn salts (control). The replacement of inorganic forms with glycinates contributed to an increase in the number of laid eggs with a concomitant lower share of rejected eggs. The supplementation of organic forms of minerals improved mineral absorption and bioavailability in blood serum as well as in the egg yolk of experimental groups. Egg yolk fat was characterized by a higher proportion of polyunsaturated fatty acids and a favorable ratio of PUFA ω-3/ω-6. The proposed nutritional supplementation of the pheasant’s diet might be a good strategy for increasing the nutritional reserves of poultry and improving their reproduction.

Development and Pharmacokinetics of a Novel Acetylsalicylic Acid Dry Powder for Pulmonary Administration.

Aspirin is an historic blockbuster product, and it has been proposed in a wide range of formulas. Due to exacerbation risks, the pulmonary route has been seldom considered as an alternative to conventional treatments. Only recently, owing to overt advantages, inhalable acetylsalicylic acid dry powders (ASA DPI) began to be considered as an option. In this work, we developed a novel highly performing inhalable ASA DPI using a nano spray-drying technique and leucine as an excipient and evaluated its pharmacokinetics compared with oral administration. The formulation obtained showed remarkable respirability and quality features. Serum and lung ASA DPI profiles showed faster presentation in blood and higher retention compared with oral administration. The dry powder was superior to the DPI suspension. The relative bioavailability in serum and lungs claimed superiority of ASA DPI over oral administration, notwithstanding a fourfold lower pulmonary dose. The obtained ASA DPI formulation shows promising features for the treatment of inflammatory and infectious lung pathologies.

Anti-malarial effect of a combination of risedronate and azithromycin against Plasmodium yoelii nigeriensis infection in Swiss mice.

Combination therapy is used to retard the selection of malaria parasite strains resistant to individual components of a combination of drugs. This approach has proved to be a success in the combination of sulphadoxine and pyrimethamine, which targets two different steps in the folate pathway of malaria parasites. However, after the success of this therapeutic combination, the efficacy of other combinations of drugs that target different enzymes in a particular metabolic pathway has, apparently, not been reported. In the current study, the antimalarial effect of a combination of risedronate (RIS), which is known for its anti-osteoporosis activity, and azithromycin (AZT) was investigated. Peter's suppression test was carried out on mice infected with 1×107P. yoelii infected erythrocytes. Drug efficacy was analyzed by comparing the percent reduction in parasitaemia on day 4 post-infection. RIS was observed to be a blood schizonticidal agent against P. yoelii infection which showed ED50 7.0 (4.04-12.13) mg/kg/day x 4. Normalized isobologram showed additive action between RIS 1mg/kg/day x 4 and AZT 10mg/kg/day x 4, and antagonistic action for the rest of the combinations (RIS 1+AZT 20, RIS 1+AZT 40, RIS 5+AZT 10, RIS 5+AZT 20, RIS 5+AZT 40, RIS 10+AZT 10, RIS 10+AZT 20 and RIS 10+AZT 40mg/kg/day x 4). Furthermore, a combination of RIS with AZT showed inferior efficacy as compared to AZT treatment alone. This antagonistic interaction may be due to the high accumulation of AZT in WBCs, which will reduce its serum bio-availability, whereas RIS has anti-parasitic activity by increasing WBCs.

L-arginine and lisinopril supplementation protects against sodium fluoride-induced nephrotoxicity and hypertension by suppressing mineralocorticoid receptor and angiotensin-converting enzyme 3 activity.

Sodium fluoride (NaF) is one of the neglected environmental toxicants that has continued to silently cause toxicity to both humans and animals. NaF is universally present in water, soil, and atmosphere. The persistent and alarming rate of increase in cardiovascular and renal diseases caused by chemicals such as NaF in mammalian tissues has led to the use of various drugs for the treatment of these diseases. The present study aimed at evaluating the renoprotective and antihypertensive effects of L-arginine against NaF-induced nephrotoxicity. Thirty male Wistar rats (150-180g) were used in this study. The rats were randomly divided into five groups of six rats each as follows: Control, NaF (300ppm), NaF + L-arginine (100mg/kg), NaF + L-arginine (200mg/kg), and NaF + lisinopril (10mg/kg). Histopathological examination and immunohistochemistry of renal angiotensin-converting enzyme (ACE) and mineralocorticoid receptor (MCR) were performed. Markers of renal damage, oxidative stress, antioxidant defense system, and blood pressure parameters were determined. L-arginine and lisinopril significantly (P < 0.05) ameliorated the hypertensive effects of NaF. The systolic, diastolic, and mean arterial blood pressure of the treated groups were significantly (P < 0.05) reduced compared with the hypertensive group. This finding was concurrent with significantly increased serum bioavailability of nitric oxide in the hypertensive rats treatedwith L-arginine and lisinopril. Also, there was a significant reduction in the level of blood urea nitrogen and creatinine of hypertensive rats treated with L-arginine and lisinopril. There was a significant (P < 0.05) reduction in markers of oxidative stress such as malondialdehyde and protein carbonyl and concurrent increase in the levels of antioxidant enzymes in the kidney of hypertensive rats treated with L-arginine and lisinopril. The results of this study suggest that L-arginine and lisinopril normalized blood pressure, reduced oxidative stress, andthe expression of renal ACE and mineralocorticoid receptor, and improved nitric oxide production. Thus, L-arginine holds promise as a potential therapy against hypertension and renal damage.

Bioavailability of a Capsaicin Lipid Multi-particulate Formulation in Rats

Background and ObjectiveBecause of the stomach-burning sensation it induces, capsaicin has been used at relatively low doses as a nutritional supplement, which has limited its bioavailability. The objective of this study was to investigate the serum bioavailability of capsaicin supplementation with or without a lipid multi-particulate (LMP) formulation.MethodsThirty-five rats were divided into five groups and administered capsaicin at either 0.2 or 1 mg/kg with or without the LMP formulation. Capsaicin bioavailability was assessed based on the area under the concentation–time curve (AUC), the time to peak concentration (Tmax), and the peak serum concentration (Cmax).ResultsFor each formulation, the capsaicin Cmax was reached at 90 min and decreased thereafter. Serum capsaicin concentrations were greater in rats administered the higher dose of capsaicin (1 mg/kg) in the LMP formulation at all measurement times (P ≤ 0.05). The AUC showed a significant increase, about 20%, when capsaicin was administered in the LMP formulation at the high dose (P = 0.002). The Tmax for oral capsaicin was similar whether or not administration was via the LMP formulation (P = 0.163). However, the Cmax of capsaicin increased in a dose-dependent manner (P < 0.05). Although the LMP formulation of the high dose of capsaicin resulted in a numerically higher Cmax, it was not statistically significantly higher (P = 0.068).ConclusionsThe present work demonstrated that administration of capsaicin via the LMP formulation significantly impacted the pharmacokinetic parameters and the serum bioavailability of orally administered 1 mg/kg capsaicin in rats. The bioavailability of capsaicin in humans may also be increased by using the LMP formulation.

Bioavailable Menthol (Transient Receptor Potential Melastatin-8 Agonist) Induces Energy Expending Phenotype in Differentiating Adipocytes.

Recent evidence supports the role of menthol, a TRPM8 agonist, in enhanced energy expenditure, thermogenesis and BAT-like activity in classical WAT depots in a TRPM8 dependent and independent manner. The present study was designed to analyse whether oral and topical administration of menthol is bioavailable at subcutaneous adipose tissue and is sufficient to directlyinduce desired energy expenditure effects. GC-FID was performed to study menthol bioavailability in serum and subcutaneous white adipose tissue following oral and topical administration. Further, 3T3L1 adipocytes were treated with bioavailable menthol doses and different parameters (lipid accumulation, “browning/brite” and energy expenditure gene expression, metal analysis, mitochondrial complex’s gene expression) were studied. No difference was observed in serum levels but significant difference was seen in the menthol concentration on subcutaneous adipose tissues after oral and topical application. Menthol administration at bioavailable doses significantly increased “browning/brite” and energy expenditure phenotype, enhanced mitochondrial activity related gene expression, increased metal concentration during adipogenesis but did not alter the lipid accumulation as well as acute experiments were performed with lower dose of menthol on mature adipocytes In conclusion, the present study provides evidence that bioavailable menthol after single oral and topical administration is sufficient to induce “brite” phenotype in subcutaneous adipose tissue However, critical dose characterization for its clinical utility is required.

Effects of the highly COX-2-selective analgesic NSAID etoricoxib on the rate of orthodontic tooth movement and cranial growth

BackgroundNSAID analgesics have found widespread use in the treatment of pain, inflammation and fever. The highly COX-2-selective NSAID etoricoxib has shown a favorable side effect profile and excellent analgesic efficacy, particularly for dental and orthodontic pain, surpassing the current standard analgesic in orthodontics, acetaminophen. However, potential side effects on the rate of orthodontic tooth movement (OTM) and cranial growth, relevant for clinical usability during orthodontic treatment, have not yet been investigated. Material and methods40 male Fischer344 rats were randomly assigned to 4 groups (n=10) — controls receiving only 1.5ml tap water per day by oral gavage for a total of 5 weeks (1) as well as rats receiving an additional daily normal etoricoxib dosage of 7.8mg/kg for 3d (2) and 7d/week (3) and a high dosage of 13.1mg/kg for 7d/week (4) with serum bioavailability assessed by liquid chromatography–mass spectrometry. After one week of premedication, the first upper left molars (M1) were moved orthodontically in anterior direction for 4 weeks using a closed NiTi coil spring (0.25N) and OTM as well as sagittal cranial growth were quantified cephalometrically by CBCT imaging at the start and end of OTM. ResultsOTM, quantified as anterior metric tipping of M1, was significantly inhibited by about 33% only in rats receiving high-dose etoricoxib 7d/week (p=0.046) with a respective, but insignificant tendency also detectable for the normal dosages, whereas sagittal cranial growth was by tendency slightly increased with rising etoricoxib dosages, reflected by corresponding steady-state serum concentrations, confirming etoricoxib bioavailability. ConclusionsAn etoricoxib-induced clinically relevant deceleration of OTM is not to be expected at dosage regimens used in clinical practice to treat dental or orthodontic pain in contrast to a continuously administered high dosage. Due to its favorable side effect profile and higher analgesic efficiency regarding dental and orthodontic pain, etoricoxib should be a clinically valid alternative to the current standard orthodontic analgesic acetaminophen with its associated higher risk profile.

Exercise preconditioning and low dose copper nanoparticles exhibits cardioprotection through targeting GSK-3β phosphorylation in ischemia/reperfusion induced myocardial infarction

BackgroundDrinking water from copper vessels and aerobic exercise have been the known facts for cardioprotection. Our previous report explored the significant cardioprotective potential of copper and exercise training by increasing phosphorylation of GSK-3β and anti-oxidant potential. ObjectivePresent study focuses the therapeutic potential of CuNP and exercise training through their molecular interaction with GSK-3β, inflammatory cytokinin, oxidative stress and necrosis. MethodsThe Myocardial damage was assessed by estimating the serum nitrite/nitrate concentration, increased CKMB, LDH, cTnI level, oxidative stress, inflammatory cytokinin and structural abnormalities in I/R insulted rats. Expression of Akt/pAkt and GSK-3β/pGSK-3β was measured by western blotting. ResultTreatment with CuNP (1 mg/kg/day, p.o., 4 weeks) and exercise training (swimming, 90 min/4 weeks) either alone or in combination markedly reduced I/R induced myocardial damage by attenuating biochemical and structural alteration. A significant reduction in oxidative stress and inflammatory mediators were observed in CuNP and exercise training treatment against I/R insulted rats. Moreover, improved serum NO bioavailability was observed in CuNP and exercise treated rats. Wortmannin associated blockage of cardioprotection induced by CuNP and exercise training and up-regulation of pAkt and pGSK-3β in I/R insulted heart confirmed the GSK-3β phosphorylation potential of CuNP and exercise training and -associated cardioprotection. ConclusionTreatment with CuNP and exercise training either alone or in combination favourably phosphorylate GSK-3β kinase pathways and further diminish oxidative stress, inflammatory cytokines, apoptosis and increase serum bioavailability of NO in the I/R insulted rats which tends to protect myocardial damage.

Mucosal absorption of therapeutic peptides by harnessing the endogenous sorting of glycosphingolipids.

Transport of biologically active molecules across tight epithelial barriers is a major challenge preventing therapeutic peptides from oral drug delivery. Here, we identify a set of synthetic glycosphingolipids that harness the endogenous process of intracellular lipid-sorting to enable mucosal absorption of the incretin hormone GLP-1. Peptide cargoes covalently fused to glycosphingolipids with ceramide domains containing C6:0 or smaller fatty acids were transported with 20-100-fold greater efficiency across epithelial barriers in vitro and in vivo. This was explained by structure-function of the ceramide domain in intracellular sorting and by the affinity of the glycosphingolipid species for insertion into and retention in cell membranes. In mice, GLP-1 fused to short-chain glycosphingolipids was rapidly and systemically absorbed after gastric gavage to affect glucose tolerance with serum bioavailability comparable to intraperitoneal injection of GLP-1 alone. This is unprecedented for mucosal absorption of therapeutic peptides, and defines a technology with many other clinical applications.

Glutathione conjugated polyethylenimine on the surface of Fe3O4 magnetic nanoparticles as a theranostic agent for targeted and controlled curcumin delivery

Theranostics with the ability to simultaneous monitoring of treatment progress and controlled delivery of therapeutic agents has become as an emerging therapeutic paradigm in cancer therapy. In this study, we have developed a novel surface functionalized iron oxide nanoparticle using polyethyleneimine and glutathione for targeted curcumin (CUR) delivery and acceptable pH sensitive character. The developed magnetic nanoparticles (MNPs) were physicochemically characterized by FT-IR, XRD, FE-SEM and TEM. The MNPs was obtained in spherical shape with diameter of 50 nm. CUR was efficiently loaded into the MNPs and then in vitro release analyses were evaluated and showed that the prepared MNPs could release higher amount of CUR in acidic medium compared to neutral medium due to the pH sensitive property of the coated polymer. MTT assay confirmed the superior toxicity of CUR loaded MNPs compared to the control nanoparticles. Higher cellular uptake of the MNPs than negative control cells was demonstrated in SK-N-MC cell line. In vitro assessment of MRI properties showed that synthesized MNPs could be used as MRI imaging agent. Furthermore, according to hemolysis assay, the developed formulation exhibited suitable hemocompatibility. In vivo blood circulation analysis of the MNPs also exhibited enhanced serum bioavailability up to 2.5 fold for CUR loaded MNPs compared with free CUR.

Bioavailability of transgenic microRNAs in genetically modified plants

BackgroundTransgenic expression of small RNAs is a prevalent approach in agrobiotechnology for the global enhancement of plant foods. Meanwhile, emerging studies have, on the one hand, emphasized the potential of transgenic microRNAs (miRNAs) as novel dietary therapeutics and, on the other, suggested potential food safety issues if harmful miRNAs are absorbed and bioactive. For these reasons, it is necessary to evaluate the bioavailability of transgenic miRNAs in genetically modified crops.ResultsAs a pilot study, two transgenic Arabidopsis lines ectopically expressing unique miRNAs were compared and contrasted with the plant bioavailable small RNA MIR2911 for digestive stability and serum bioavailability. The expression levels of these transgenic miRNAs in Arabidopsis were found to be comparable to that of MIR2911 in fresh tissues. Assays of digestive stability in vitro and in vivo suggested the transgenic miRNAs and MIR2911 had comparable resistance to degradation. Healthy mice consuming diets rich in Arabidopsis lines expressing these miRNAs displayed MIR2911 in the bloodstream but no detectable levels of the transgenic miRNAs.ConclusionsThese preliminary results imply digestive stability and high expression levels of miRNAs in plants do not readily equate to bioavailability. This initial work suggests novel engineering strategies be employed to enhance miRNA bioavailability when attempting to use transgenic foods as a delivery platform.

Abstract 194: Effective targeting of MYC expression with a novel nucleic acid binding (G4-quadruplex) small molecule coupled with HDAC inhibition synergizes to limit myeloma growth

Abstract MYC is deregulated in many malignancies and its aberrant expression is associated with tumorigenesis and tumor maintenance. We employed a therapeutic strategy to target both MYC transcription, and protein stability. Previously, we developed a small molecule microarray and screened it for MYC G4-binding compounds. The stabilization of G-quadraplex (G4) structures by nucleic acid binding small molecules in the NHE III region of the MYC promoter slows MYC transcription. We identified a benzofuran containing small molecule that could selectively and reversibly stabilize MYC-G4 DNA and reduce MYC expression. This compound demonstrated a G4-dependent mechanism of action showing toxicity in multiple myeloma cell lines containing a G4 in their MYC promoter whereas minimal effects were seen in a Burkitt’s lymphoma line lacking the MYC G4 sequence. Gene expression analysis validated that this compound selectively inhibited MYC and other MYC effectors, but did little to limit the expression of other G4 containing genes. The synthesis of more than 15 analogs identified a new benzofuran-containing analog with enhanced inhibitory activity in a diverse panel of human cancer cell lines (NCI-60), including a number of myeloma cell lines. EDGE-seq data confirmed that the new analog is similar to the original compound in having higher affinity for the G4 in MYC compared to the G4 in BCL2, KRAS, VEGFA and HIF1A. In addition, the analog was synergistic with entinostat, an HDAC inhibitor that can affect MYC protein stability, in limiting myeloma cells, but not PBMCs. The more potent growth inhibitory activity of the new analog allowed us to generate sufficient quantities to evaluate its pharmacokinetics and toxicity in mice. The compound was well tolerated in a dose-escalation toxicity study; no adverse effects were observed and preliminary pharmacokinetic studies showed promising serum bioavailability and exposure properties when administered either intravenously, intraperitoneally or orally. In an assessment of short term in vivo activity, MYC protein expression was inhibited in multiple myeloma xenografts. Longer term studies to evaluate the anti-tumor activity of the compound are currently in progress. Thus, our data provide evidence that small molecule stabilization of the MYC G4 can drive transcriptional silencing of oncogenic MYC both in vitro and in vivo. Furthermore, synergistic tumor cell killing was achieved when the MYC G4 inhibitor was coupled with HDAC inhibition. Citation Format: Snehal M. Gaikwad, David R. Calabrese, Elena C. Leon, John K. Simmons, Shuling Zhang, Aleksandra Michalowski, Sayeh Gorjifard, Zaw Phyo, Daniel Connors, John S. Schneekloth, Beverly A. Mock. Effective targeting of MYC expression with a novel nucleic acid binding (G4-quadruplex) small molecule coupled with HDAC inhibition synergizes to limit myeloma growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 194. doi:10.1158/1538-7445.AM2017-194

Prevention of Surgical Site Infections and Biofilms: Pharmacokinetics of Subcutaneous Cefazolin and Metronidazole in a Tumescent Lidocaine Solution.

Tumescent anesthesia antibiotic delivery (TAAD) consists of subcutaneous infiltration of antibiotic(s) dissolved tumescent lidocaine anesthesia. Tumescent lidocaine anesthesia contains lidocaine (≤ 1 g/L), epinephrine (≤ 1 mg/L), sodium bicarbonate (10 mEq/L) in 0.9% saline. Our aim was to measure cefazolin and metronidazole concentrations over time in subcutaneous tumescent interstitial fluid (TISF) after TAAD, in serum after TAAD and after intravenous antibiotic delivery (IVAD). We hypothesize that the pharmacokinetic/pharmacodynamic profiles of TAAD + IVAD are superior to IVAD alone for the prevention of surgical site infections and biofilms. Concentrations of cefazolin and metronidazole in TISF and serum following TAAD and in serum following IVAD were compared in 5 female volunteers. Subjects received cefazolin or cefazolin plus metronidazole by IVAD alone and by TAAD alone. One subject also received concomitant IVAD and TAAD of these 2 antibiotics. Sequential samples of serum or subcutaneous TISF were assayed for antibiotic concentration. Cefazolin (1 g) by TAAD resulted in an area under the curve of the concentration-time profile and a maximum concentration (Cmax) in subcutaneous tissue that were 16.5 and 5.6 times greater than in serum following 1 g by IVAD. Metronidazole (500 mg) by TAAD resulted in an area under the curve and Cmax that were 8.1 and 24.7 times greater in TISF, than in serum after 500 mg by intravenous delivery. IVAD + TAAD resulted in superior antibiotic concentrations to IVAD alone. TAAD + IVAD produced superior antibiotic bioavailability in both subcutaneous interstitial fluid and serum compared with IVAD alone. There was no evidence that TAAD of cefazolin and metronidazole poses a significant risk of harm to patients.

Abstract 322: Selective inhibition of MYC expression by a small molecule G-quadruplex stabilizer

Abstract MYC overexpression or amplification is commonly seen in a wide variety of tumor types, including multiple myeloma. Although MYC appears to be an important driver of the oncogenic phenotype, the helix-loop-helix topology, short half-life, and rapid replenishment of its encoded protein make it a particularly challenging drug target. However, the promoter region of the MYC gene contains a G-quadruplex (G4) DNA secondary structure that can be stabilized to block transcription. Recently, we reported the identification of a compound from a small molecule microarray screen that selectively binds the MYC G4, compared with other oncogenes that also contain G4s, and inhibits MYC mRNA and protein expression, leading to cell cycle arrest in human multiple myeloma cell lines (ACS Chem Biol. 2015). Here we describe the in vitro and in vivo evaluation of a more potent analog that retains the selectivity of the original compound for the MYC G4 sequence. After observing strong growth inhibitory activity of this new compound in a diverse panel of human cancer cell lines, we evaluated its pharmacokinetic and toxicity profiles in mice. Preliminary pharmacokinetic studies showed promising serum bioavailability and exposure properties when administered either intravenously or intraperitoneally. The compound was well tolerated in a month long, dose-escalation toxicity study in mice receiving daily administration of the compound. No adverse effects were observed during the study. In an assessment of short term in vivo activity, MYC expression was inhibited in multiple myeloma xenografts. More long-term studies to evaluate the anti-tumor activity of the compound are currently in progress. Thus, our data provide evidence that small molecule stabilization of the MYC G4 can drive transcriptional silencing of oncogenic MYC expression both in vitro and in vivo. Citation Format: Elena C. Leon, John K. Simmons, David Calabrese, Wendy DuBois, Kenneth Felsenstein, Lindsey B. Saunders, Shuling Zhang, Aleksandra Michalowski, Frank Gonzalez, Beverly A. Mock, John S. Schneekloth. Selective inhibition of MYC expression by a small molecule G-quadruplex stabilizer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 322.

Identification and Testing of Novel CARP-1 Functional Mimetic Compounds as Inhibitors of Non-Small Cell Lung and Triple Negative Breast Cancers.

The triple negative breast cancer (TNBCs) and non-small cell lung cancers (NSCLCs) often acquire mutations that contribute to failure of drugs in clinic and poor prognosis, thus presenting an urgent need to develop new and improved therapeutic modalities. Here we report that CARP-1 functional mimetic (CFMs) compounds 4 and 5, and 4.6, a structurally related analog of CFM-4, are potent inhibitors of TNBC and NSCLC cells in vitro. Cell growth suppression by CFM-4 and -4.6 involved interaction and elevated expression of CARP-1/CCAR1 and Death Effector Domain (DED) containing DNA binding (DEDD)2 proteins. Apoptosis by these compounds also involved activation of pro-apoptotic stress-activated kinases p38 and JNK1/2, cleavage of PARP and loss of mitotic cyclin B1. Both the CFMs inhibited abilities of NSCLC and TNBC cells to migrate, invade, and form colonies in suspension, while disrupting tubule formation by the human umbilical vein endothelial cells (HUVECs). Nano-lipid formulation of CFM-4 (CFM-4 NLF) enhanced its serum bioavailability when compared with the free CFM-4. Oral administration of CFM-4 NLF reduced weights and volume of the xenografted tumors derived from A549 NSCLC and MDA-MB-231 TNBC cells. Although no gross tissue or histological toxicities were noticed, the immuno-histochemical analysis revealed increased CARP-1 and DNA fragmentation in tumors of the CFM-4 NLF-treated animals. In conclusion, while stimulation of pro-apoptotic CARP-1 and DEDD2 expression and their binding underscore a novel mechanism of apoptosis transduction by CFM compounds, our proof-of-concept xenograft studies demonstrate therapeutic potential of CFM-4 for TNBC and NSCLC.

Zidovudine

Zidovudine

Investigation of medication administration through catheters in intensive care

This study aims to identify errors in medication administration through probes and characterize the interruption or not of nutrition in the case of drugs that require relative fasting. This is an epidemiological, cross-sectional and observational study in intensive care with a sample of 350 doses of drugs administered by 56 nursing technicians. The results showed no pause between the drug administration and the infusion of enteral feeding in 116 (33.14%) doses of drugs that required relative fasting, including captopril, sodic warfarin, sodic levothyroxine, sodic digoxin and sodic phenytoin. The irrigation of probes did not occur (94.28%) in most cases. It is concluded that the serum bioavailability of the drugs mentioned may have been reduced, compromising their therapeutic efficacy; and that the lack of probe irrigation with sterile water before administering drugs shows the absence of a specific and fundamental care to prevent probe clogging.

41 Pharmacokinetics of nasally administered tobramycin, colistin sulphomethate sodium and a combination of tobramycin and colistin sulphomethate sodium

The paranasal sinuses can constitute a niche for bacteria which can migrate to the lungs. Nasal administration of antibiotics may be effective, but safety of this treatment has to be established first. Objectives: Investigation of the pharmacokinetics (PK) of nasally administered tobramycin (T), colistin sulphomethate sodium (CSS) and a combination of both drugs using systemic absorption, expressed as % absorbed, as surrogate for safety. In addition, tolerability of the nasal irrigations was examined. Methods: Ten adult CF patients performed three different nasal irrigations: 300 mg of T, 2 million IU of CSS and 300 mg of T combined with 2 million IU of CSS. Serum concentrations T and CSS were analysed using a validated assay. Individual PK parameters were calculated and assimilated with T and colistin serum values using a computerized CF-based population model. Maximum serum level (Cmax), trough serum level (Ctrough ) and bioavailability (F) were calculated. T Cmax >30 mg/L and Ctrough >0.5 mg/L were considered to be toxic. For colistin toxic levels are not known. Tolerability was measured using a Visual Analog Scale (VAS). Results: Following the T and the combined irrigation only 2 patients had detectable tobramycin serum levels with a Cmax