Mathematical Analysis of a COVID-19 Epidemic Model by Using Data Driven Epidemiological Parameters of Diseases Spread in India

This paper attempts to describe the outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19) via an epidemic model. This virus has dissimilar effects in different countries. The number of new active coronavirus cases is increasing gradually across the globe. India is now in the second stage of COVID-19 spreading, it will be an epidemic very quickly if proper protection is not undertaken based on the database of the transmission of the disease. This paper is using the current data of COVID-19 for the mathematical modeling and its dynamical analysis. We bring in a new representation to appraise and manage the outbreak of infectious disease COVID-19 through SEQIR pandemic model, which is based on the supposition that the infected but undetected by testing individuals are send to quarantine during the incubation period. During the incubation period if any individual be infected by COVID-19, then that confirmed infected individuals are isolated and the necessary treatments are arranged so that they cannot taint the other residents in the community. Dynamics of the SEQIR model is presented by basic reproduction number R ₀ and the comprehensive stability analysis. Numerical results are depicted through apt graphical appearances using the data of five states and India.

Mathematical Analysis of a COVID-19 Epidemic Model by Using Data Driven Epidemiological Parameters of Diseases Spread in India

This paper attempts to describe the outbreak of Severe Acute Respiratory Syndrome Coronavirus 2 (COVID-19) via an epidemic model. This virus has dissimilar effects in different countries. The number of new active coronavirus cases is increasing gradually across the globe. India is now in the second stage of COVID-19 spreading, it will be an epidemic very quickly if proper protection is not undertaken based on the database of the transmission of the disease. This paper is using the current data of COVID-19 for the mathematical modeling and its dynamical analysis. We bring in a new representation to appraise and manage the outbreak of infectious disease COVID-19 through SEQIR pandemic model, which is based on the supposition that the infected but undetected by testing individuals are send to quarantine during the incubation period. During the incubation period if any individual be infected by COVID-19, then that confirmed infected individuals are isolated and the necessary treatments are arranged so that they cannot taint the other residents in the community. Dynamics of the SEQIR model is presented by basic reproduction number R 0 and the comprehensive stability analysis. Numerical results are depicted through apt graphical appearances using the data of five states and India.

Spin-state transition of Co ion (S2S5/2) in hole substituted 1D chain of Ca3Co2O6

We have discovered spin-state transition (S= 2 toS= 5/2) of Co ions due to Mg substitution in the Ca₃Co₂O₆apparent in the magnetic susceptibility, x-ray photoelectron spectroscopy (XPS), and first-principles study. We also examine the effect of Mg substitution on the magnetic and electronic structure of Ca₃Co₂O₆by first-principles calculations. It involves generalized gradient approximation with Coulomb interaction (U) in exchange-correlation energy functional. Our study shows a reasonable agreement between effective magnetic moment (μ_eff) determined from the Curie-Weiss fit with that from the XPS analysis and first-principles calculations study. We have attributed the decrease in positive intra-chain exchange interaction constant (J₁/k_B) to the antiferromagnetically coupled induced Co⁴⁺ions (S= 5/2) arising from the Mg²⁺ions substitution. The in-field metamagnetic transitions in the isothermalM(H) curves below the critical field (H_c) have been accurately mapped and successfully explained by the change in magnetic entropy (ΔS) calculations and Arrott plots. Electronic structure study reveals hole-type doping of Mg atom, and the Fermi level (E_F) shifts below. Density of state and band structure calculation indicates strong hybridization between partial states of Co-3d and O-2p orbitals for the Mg-doped compound due to which the band crossing at Fermi level is observed, and a hole-type Fermi surface is formed.

1534 A rare operation: resection of a complex malignant peripheral nerve sheath tumour deemed inoperable by a national centre

We present this rare case which was led by spinal surgeons at Leeds after being deemed not suitable for operative input by a national centre.

A 54-year-old lady who presented with 2-month history of worsening left flank pain on a background of four years. She was otherwise fit and well. CT confirmed aggressive left-sided paraspinal tumour with epidural encroachment, extending from T8 to T10 vertebral levels. Its deep surface was well-defined and extending superficially through the chest wall with destruction of ribs. The mass grew in size in course of days requiring urgent attention due to risk of cord compression. Biopsy proved high grade MPNST.

Malignant peripheral nerve sheath tumor (MPNST) is a rare type of sarcoma, 5-10% of sarcoma cases. MPNST is most common in young adults and middle-aged adults. About 25% to 50% of people with MPNST have NF1. 8% to 13% of people with NF1 will get MPNST in their lifetime.

An MDT approach involving spinal, thoracic, vascular and plastic surgeons opined it requiring extensive surgery due to its complexity. It was performed in stages – embolisation then aortic stent placement followed by final resection of the tumour with chest well reconstruction using an LD flap.

A multidisciplinary and multispecialty approach has led to a positive prognosis for this patient who is on the road to recovery.

Design and Simulation of Extended Interaction Cavities for a Ka band Multi beam Klystron

This article reports about the design approach, electromagnetic simulation and analysis results of high-frequency ladder-type input, output, and intermediate RF cavaties for Ka-band multi-beam extended interaction klystron. Several parameters of the cavity, such as quality factor, shunt impedance, etc., have been investigated by the assistance of electromagnetic software CST microwave studio.

Octreotide-Targeted Lcn2 siRNA PEGylated Liposomes as a Treatment for Metastatic Breast Cancer

Lcn2 overexpression in metastatic breast cancer (MBC) can lead to cancer progression by inducing the epithelial-to-mesenchymal transition and enhancing tumor angiogenesis. In this study, we engineered a PEGylated liposomal system encapsulating lipocalin 2 (Lcn2) small interfering RNA (Lcn2 siRNA) for selective targeting MBC cell line MCF-7 and triple-negative breast cancer cell line MDA-MB-231. The PEGylated liposomes were decorated with octreotide (OCT) peptide. OCT is an octapeptide analog of somatostatin growth hormone, having affinity for somatostatin receptors, overexpressed on breast cancer cells. Optimized OCT-targeted Lcn2 siRNA encapsulated PEGylated liposomes (OCT-Lcn2-Lipo) had a mean size of 152.00 nm, PDI, 0.13, zeta potential 4.10 mV and entrapment and loading efficiencies of 69.5% and 7.8%, respectively. In vitro uptake and intracellular distribution of OCT-Lcn2-Lipo in MCF-7 and MDA-MB-231 and MCF-12A cells demonstrated higher uptake for the OCT-targeted liposomes at 6 h by flow cytometry and confocal microscopy. OCT-Lcn2-lipo could achieve approximately 55-60% silencing of Lcn2 mRNA in MCF-7 and MDA-MB-231 cells. OCT-Lcn2-Lipo also demonstrated in vitro anti-angiogenic effects in MCF-7 and MDA-MB-231 cells by reducing VEGF-A and reducing the endothelial cells (HUVEC) migration levels. This approach may be useful in inhibiting angiogenesis in MBC.

Spin induced exchange bias and lattice modulation in Nd1-x Eu x CrO3

We report the evolution of coupled phonons and exchange bias (EB) in perovskite-type Nd1-x Eu x CrO3 (x = 0.0, 0.05, and 0.10) samples by means of temperature-dependent Raman spectroscopy and dc magnetization measurements. We observed a non-monotonic behavior of the EB field around the temperature T *, which lies between the antiferromagnetic ordering temperature (T N) and spin-reorientation transition temperature (T SR). The temperature dependence of phonon modes related to antistretching and bending of CrO6 octahedra and Nd3+/Eu3+ ion vibration below T N confirms the strong spin-phonon coupling. The T * found from the non-monotonicity of the EB is imprinted with the additional anomaly observed in the low-temperature spin-phonon behavior. The phonon modes and phonon anomaly are also verified using the density functional theory-based calculations.

Hyaluronic Acid-Targeted Stimuli-Sensitive Nanomicelles Co-Encapsulating Paclitaxel and Ritonavir to Overcome Multi-Drug Resistance in Metastatic Breast Cancer and Triple-Negative Breast Cancer Cells

Active targeting and overcoming multi-drug resistance (MDR) can be some of the important attributes of targeted therapy for metastatic breast cancer (MBC) and triple-negative breast cancer (TNBC) treatment. In this study, we constructed a hyaluronic acid (HA)-decorated mixed nanomicelles-encapsulating chemotherapeutic agent paclitaxel (PTX) and P-glycoprotein inhibitor ritonavir (RTV). HA was conjugated to poly (lactide) co-(glycolide) (PLGA) polymer by disulfide bonds (HA-ss-PLGA). HA is a natural ligand for CD44 receptors overexpressed in breast cancer cells. Disulfide bonds undergo rapid reduction in the presence of glutathione, present in breast cancer cells. The addition of RTV can inhibit the P-gp and CYP3A4-mediated metabolism of PTX, thus aiding in reversing MDR and sensitizing the cells toward PTX. An in vitro uptake and cytotoxicity study in MBC MCF-7 and TNBC MDA-MB-231 cell lines demonstrated the effective uptake of the nanomicelles and drug PTX compared to non-neoplastic breast epithelium MCF-12A cells. Interestingly, in vitro potency determination showed a reduction in mitochondrial membrane potential and reactive oxygen species in breast cancer cell lines, indicating effective apoptosis of cancer cells. Thus, stimuli-sensitive nanomicelles along with HA targeting and RTV addition can effectively serve as a chemotherapeutic drug delivery agent for MBC and TNBC.

Preparation and characterization of lutein loaded folate conjugated polymeric nanoparticles

AIM

To prepare and characterise lutein-loaded polylactide-co-glycolide-polyethylene glycol-folate (PLGA-PEG-FOLATE) nanoparticles and evaluate enhanced uptake in SK-N-BE(2) cells.

METHODS

Nanoparticles were prepared using O/W emulsion solvent evaporation and characterised using DLS, SEM, DSC, FTIR and in-vitro release. Lutein-uptake in SK-N-BE(2) cells was determined using flow-cytometry, confocal-microscopy and HPLC. Control was lutein PLGA nanoparticles.

RESULTS

The size of lutein-loaded PLGA and PLGA-PEG-FOLATE nanoparticles were 189.6 ± 18.79 nm and 188.0 ± 4.06 nm, respectively. Lutein entrapment was ∼61%(w/w) and ∼73%(w/w) for PLGA and PLGA-PEG-FOLATE nanoparticles, respectively. DSC and FTIR confirmed encapsulation of lutein into nanoparticles. Cellular uptake studies showed ∼1.6 and ∼2-fold enhanced uptake of lutein from PLGA-PEG-FOLATE nanoparticles compared to PLGA nanoparticles and lutein, respectively. Cumulative release of lutein was higher in PLGA nanoparticles (100% (w/w) within 24 h) compared to PLGA-PEG-FOLATE nanoparticles (∼80% (w/w) in 48 h).

CONCLUSION

Lutein-loaded PLGA-PEG-FOLATE nanoparticles could be a potential treatment for hypoxic ischaemic encephalopathy.

Prodrugs and nanomicelles to overcome ocular barriers for drug penetration

INTRODUCTION

Ocular barriers hinder drug delivery and reduce drug bioavailability. This article focuses on enhancing drug absorption across the corneal and conjunctival epithelium. Both, transporter targeted prodrug formulations and nanomicellar strategy is proven to enhance the drug permeation of therapeutic agents across various ocular barriers. These strategies can increase aqueous drug solubility and stability of many hydrophobic drugs for topical ophthalmic formulations.

AREAS COVERED

The article discusses various ocular barriers, ocular influx, and efflux transporters. It elaborates various prodrug strategies used for enhancing drug absorption. Along with this, the article also describes nanomicellar formulation, its characteristic and advantages, and applications in for anterior and posterior segment drug delivery.

EXPERT OPINION

Prodrugs and nanomicellar formulations provide an effective strategy for improving drug absorption and drug bioavailability across various ocular barriers. It will be exciting to see the efficacy of nanomicelles for treating back of the eye disorders after their topical application. This is considered as a holy grail of ocular drug delivery due to the dynamic and static ocular barriers, restricting posterior entry of topically applied drug formulations.

Investigation of emission characteristics of NMVOCs over urban site of western India

This is the first study to characterize the variation and emission of C₂-C₅ non-methane volatile organic compounds (NMVOCs) in a semi-urban site of western India based on measurements during February-December 2015. Anthropogenic NMVOCs show clear seasonal dependence with highest in winter and lowest in monsoon season. Biogenic NMVOCs likes isoprene show highest mixing ratios in the pre-monsoon season. The diurnal variation of NMVOC species can be described by elevated values from night till morning and lower values in the afternoon hours. The elevated levels of NMVOCs during night and early morning hours were caused mainly by weaker winds, temperature inversion and reduced chemical loss. The correlations between NMVOCs, CO and NOx indicate the dominant role of various local emission sources. Use and leakage of liquefied petroleum gas (LPG) contributed to the elevated levels of propane and butanes. Mixing ratios of ethylene, propylene, CO, NOx, etc. show predominant emissions from combustion of fuels in automobiles and industries. The Positive Matrix Factorization (PMF) source apportionments were performed for the seven major emission sectors (i.e. Vehicular exhaust, Mixed industrial emissions, Biomass/Fired brick kilns/Bio-fuel, Petrochem, LPG, Gas evaporation, Biogenic). Emissions from vehicle exhaust and industry-related sources contributed to about 19% and 40% of the NMVOCs, respectively. And the rest (41%) was attributed to the emissions from biogenic sources, LPG, gasoline evaporation and biomass burning. Diurnal and seasonal variations of NMVOCs were controlled by local emissions, meteorology, OH concentrations, long-range transport and planetary boundary layer height. This study provides a good reference for framing environmental policies to improve the air quality in western region of India.

Self-Assembling Topical Nanomicellar Formulation to Improve Curcumin Absorption Across Ocular Tissues

The pathophysiological mechanisms for dry and wet age-related macular degeneration (AMD) involve oxidative stress and increased VEGF release and expression. An ideal drug candidate for both types of AMD is the one which offers significant protection to the retinal cells from oxidative stress and inhibit VEGF release. Curcumin is one such natural product which provides numerous beneficial effects including antioxidant, anti-inflammatory, and anti-VEGF activities and has the potential for the treatment of both types of AMD. The bioavailability of curcumin is negligible due to its poor aqueous solubility. The purpose of this work is to develop an aqueous nanomicellar drop formulation of curcumin (CUR-NMF) for back of the eye delivery utilizing hydrogenated castor oil (HCO-40) and octoxynol-40 (OC-40) to treat AMD. A full factorial design was performed with JMP software analysis to optimize the formulation size, polydispersity index (PDI), entrapment efficiency, loading, and precipitation. MTT and LDH assays on human retinal pigmented epithelial (D407) cells revealed that 5-10 μM CUR-NMF dose is safe for ophthalmic use. Furthermore, CUR-NMF exhibited significant protection of retinal (D407) cells against H₂O₂-induced oxidative stress. In vitro drug release kinetics suggested a sustained drug release profile indicating a long-term protection ability of CUR-NMF against oxidative stress to retinal cells. In addition, an ELISA suggested that CUR-NMF significantly reduces vascular endothelial growth factor (VEGF) release in D407 cell line, hence diminishes the risk of angiogenesis. Collectively, these results suggest that the proposed CUR-NMF can be tremendously effective in treating both types of AMD.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Predicting gas phase entropy of select hydrocarbon classes through specific information-theoretical molecular descriptors

The usefulness of five specific information-theoretical molecular descriptors was investigated for predicting the gas phase entropy of selected classes of acyclic and cyclic compounds. Among them, total information on atomic number (TI^Z), graph vertex complexity (H^V) and total information on bonds (TIB^AT), considered together showed the best correlation along with a low standard deviation (r² = 0.97, s = 21.14) with gas phase entropy values of 130 compounds. The multiple regression equation treating these three indices as independent variables was statistically highly significant which was evident from the F-statistics. In particular, very small difference between r² and r²-pred values indicates that the regression model is not overfitted and is, therefore, suitable for prediction purposes. When truly used as a training set to predict (from regression equation) 40 additional compounds we get a very high correlation (r² = 0.975), which remains almost identical (r² = 0.97) for the combined data set of 170 compounds. The three indices appear to be useful descriptors producing correlation that remains stable with the change in the size of the data set. Also, the information-theoretical measures appear to capture an additive-cum-constitutive nature of gas phase entropy yielding an acceptable statistical fit.

P76 Skip laminectomy versus cervical laminectomy, an analysis of patient reported outcomes, spinal alignment and re-operation rates: the leeds spinal unit experience (2008–2016)

Objectives

To compare clinical, radiological and complication results between skip laminectomy and cervical laminectomy for posterior cervical decompression for cervical spondylotic myelopathy.

Design

Retrospective single institution cohort study.

Subjects

Subjects underwent primary skip or cervical laminectomy between 2008–2016.

Methods

Statistical analysis compared pre- and post-operative differences in Visual Analogue Scale, Neck Disability Index and radiological differences in sagittal alignment of the vertebral bodies. Analysis of re-operation rates was performed.

Results

A total of 42 and 29 patients had skip and cervical laminectomy respectively. Median follow up was 32±23.1 (Range: 1–325) weeks. Post-operatively there was no difference in patient reported outcomes namely Visual Analogue Scale and Neck Disability Index between skip laminectomy and cervical laminectomy groups compared to pre-operatively (p=0.64, p=0.75). No difference was seen in sagittal alignment between both groups following surgery (p=0.65). Three patients (7.1%) in the skip laminectomy group and two patients (6.9%) in the cervical laminectomy group required revision surgery to the cervical spinal region at a different level to the original surgery. No patients needed further instrumentation.

Conclusions

Both skip laminectomy and cervical laminectomy appear to deliver similar outcomes with regards to patient reported outcomes, preserving sagittal alignment and re-operation rates over this short follow-up period.

Multi-Layered Nanomicelles as Self-Assembled Nanocarrier Systems for Ocular Peptide Delivery

Despite the great potential of peptides as therapeutics, there is an unmet challenge in sustaining delivery of sufficient amounts in their native forms. This manuscript describes a novel nanocarrier capable of delivering functional small peptides in its native form. Self-assembling multi-layered nanomicelles composed of two polymers, polyoxyethylene hydrogenated castor oil 40 (HCO-40) and octoxynol 40 (OC-40), were designed to combine hydrophilic interaction and solvent-induced encapsulation of peptides and proteins. The polymers are employed to encapsulate peptide or protein in the core of the organo-nanomicelles which are further encapsulated with another layer of the same polymers to form an aqueous stable nanomicellar solution. The size of the multi-layered nanomicelles ranges from ~ 16 to 20 nm with zeta potential close to neutral (~ - 2.44 to 0.39 mV). In vitro release studies revealed that octreotide-loaded multi-layered nanomicelles released octreotide at much slower rate in simulated tear fluid (STF) (~ 27 days) compared to PBST (~ 11 days) in its native form. MTT assay demonstrated negligible toxicity of the multi-layered nanomicelles at lower concentrations in human retinal pigment epithelial (HRPE, D407), human conjunctival epithelial (CCL 20.2), and rhesus choroid-retinal endothelial (RF/6A) cells. This work demonstrates an efficient small peptide delivery platform with significant advantages over existing approaches, as it does not require modification of the peptide, is biodegradable, and has a small size and high loading capacity.

PSMA Antibody-Conjugated Pentablock Copolymer Nanomicellar Formulation for Targeted Delivery to Prostate Cancer

The main purpose of this study was to develop a prostate-specific membrane antigen (PSMA) antibody-conjugated drug-loaded nanomicelles using MPEG--PLA-PCL-PLA-PEG-NH2 pentablock copolymer for targeted delivery of hydrophobic anticancer drugs to prostate cancer cells. During this experiment, monomers of L-lactide, ε-caprolactone, poly(ethylene glycol)-methyl ether, and poly(ethylene glycol)-NH2 were used to prepare pentablock copolymer using the ring opening technique. The pentablock nanomicellar (PBNM) formulation was prepared by the evaporation-rehydration method. The resultant pentablock nanomicelles were then conjugated with PSMA antibody resulting in PSMA-Ab-PTX-PBNM. Both the block copolymers and the nanomicelles were analyzed by hydrogen nuclear magnetic resonance (H-NMR), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The obtained nanomicelles (NM) were then analyzed for size and zeta potential using dynamic light scattering-dynamic laser scattering (DLS) and then further submitted to H-NMR and TEM analyses. The XRD, FTIR, and the H-NMR analyses confirmed the structure of the pentablock copolymers. The average size for conjugated nanomicellar was 45 nm ± 2.5 nm. The average (ζ-potential) was around - 28 mV. H-NMR and FTIR analysis done on PSMA-coupled paclitaxel-loaded PBNM showed peaks characteristic of the drug (paclitaxel) and the polymer, confirming the successful encapsulation. TEM analysis showed well-defined spherical morphology and confirmed the size range obtained by the DLS. In vitro release studies revealed sustained slow of PTX in phosphate buffer solution (PBS). Confocal scanning microscopy (TEM) of coumarin6-loaded in PBNM indicated that pentablock nanomicelles were internalized into the prostate cancer (PC-3) cells. Cell proliferation assay showed that nanomicelles ferried paclitaxel into the PC-3 cells and subsequently reduced the cell proliferation. The results depict PTX-PBNM-Ab as a suitable carrier for targeted delivery of drugs to prostate cancer cells.

Novel Random Triblock Copolymers for Sustained Delivery of Macromolecules for the Treatment of Ocular Diseases

The objective of this study is to design, develop, and synthesize novel random triblock (RTB) copolymers for sustained delivery of macromolecules. RTB copolymers have not been utilized for the delivery of macromolecules for ocular diseases. RTB copolymers comprising of polyethylene glycol, glycolide, and ɛ-caprolactone blocks were synthesized and assessed for their molecular weights and purity using ¹H-NMR spectroscopy, gel permeation chromatography, FTIR (functionality), and XRD (crystallinity). No toxicity was observed when ocular cell lines were treated with RTB copolymers. These materials were applied for encapsulation of peptides and proteins (catalase, IgG, BSA, IgG Fab fragment, lysozyme, insulin, and octreotide) in nanoparticles. Particle size ranged from 202.41 ± 2.45 to 300.1 ± 3.11 nm depending on the molecular size and geometry of proteins/peptides. Polydispersity indices were between 0.26 ± 0.02 and 0.46 ± 0.07 respectively. Percentage entrapment efficiency and drug loading ranged from 83.44 ± 2.24 to 45.35 ± 5.53 and 21.56 ± 0.46 to 13.08 ± 1.35 respectively depending on molecular weights of peptides or proteins. A sustained in vitro release of macromolecule was observed over 3-month period. These results suggest that RTB copolymers may be suitable for sustained delivery systems for various macromolecules for different diseases including ocular diseases.

Strategic Pentablock Copolymer Nanomicellar Formulation for Paclitaxel Delivery System

Nanomicelles (NM) enhance solubility and absorption of active pharmaceutical ingredients (APIs). Various polymers and non-polymers are utilized to prepare nanomicellar formulations to achieve high absorption and delivery of drugs. The main purpose of this study was to develop drug-loaded nanomicelles with pentablock copolymers for paclitaxel delivery. Monomers of lactide, ε-caprolactone, and polyethylene-glycol were utilized to prepare pentablock copolymer by ring opening technique. The pentablock nanomicelles (PBNM) were formulated by evaporation and rehydration. Both copolymers and nanomicelles were analyzed by H-NMR, FTIR, and XRD. Nanomicelles were further analyzed for size and zeta potential using dynamic light scattering (DLS) and by H-NMR and TEM. The XRD, FTIR, and H-NMR analyses confirmed the structures of the pentablock copolymers. Average size was 20 nm ± 5.00 nm, and ζ-potential is around zero. H-NMR and FTIR analyses for Paclitaxel-PBNM indicated peaks of paclitaxel and the polymer, confirming successful encapsulation. TEM showed spherical morphology and size range similar to that obtained by DLS. In vitro release studies revealed slow first-order paclitaxel release rate from pentablock nanomicelles in phosphate buffer solution (PBS). Confocal laser scanning microscopy analysis with coumarin-6-loaded in PBNM indicated that pentablock nanomicelles were efficiently taken into prostate cancer (PC-3) cells. Cell proliferation assay showed that nanomicelles were able to ferry adequate amounts of paclitaxel drug into PC-3 cells and subsequently inhibiting PC-3 cell proliferation significantly. Results confirmed that pentablock copolymer can generate drug-loaded nanomicelles with desirable sizes and zeta potential. These demonstrate potentiality of pentablock nanomicelles as carrier for anticancer delivery.

Ocular delivery of proteins and peptides: Challenges and novel formulation approaches

The impact of proteins and peptides on the treatment of various conditions including ocular diseases over the past few decades has been advanced by substantial breakthroughs in structural biochemistry, genetic engineering, formulation and delivery approaches. Formulation and delivery of proteins and peptides, such as monoclonal antibodies, aptamers, recombinant proteins and peptides to ocular tissues poses significant challenges owing to their large size, poor permeation and susceptibility to degradation. A wide range of advanced drug delivery systems including polymeric controlled release systems, cell-based delivery and nanowafers are being exploited to overcome the challenges of frequent administration to ocular tissues. The next generation systems integrated with new delivery technologies are anticipated to generate improved efficacy and safety through the expansion of the therapeutic target space. This review will highlight recent advances in formulation and delivery strategies of protein and peptide based biopharmaceuticals. We will also describe the current state of proteins and peptides based ocular therapy and future therapeutic opportunities.

Abundant and equipotent founder cells establish and maintain acute lymphoblastic leukaemia

High frequencies of blasts in primary acute lymphoblastic leukaemia (ALL) samples have the potential to induce leukaemia and to engraft mice. However, it is unclear how individual ALL cells each contribute to drive leukaemic development in a bulk transplant and the extent to which these blasts vary functionally. We used cellular barcoding as a fate mapping tool to track primograft ALL blasts in vivo. Our results show that high numbers of ALL founder cells contribute at similar frequencies to leukaemic propagation over serial transplants, without any clear evidence of clonal succession. These founder cells also exhibit equal capacity to home and engraft to different organs, although stochastic processes may alter the composition in restrictive niches. Our findings enhance the stochastic stem cell model of ALL by demonstrating equal functional abilities of singular ALL blasts and show that successful treatment strategies must eradicate the entire leukaemic cell population.

A comprehensive insight on ocular pharmacokinetics

The eye is a distinctive organ with protective anatomy and physiology. Several pharmacokinetics compartment models of ocular drug delivery have been developed for describing the absorption, distribution, and elimination of ocular drugs in the eye. Determining pharmacokinetics parameters in ocular tissues is a major challenge because of the complex anatomy and dynamic physiological barrier of the eye. In this review, pharmacokinetics of these compartments exploring different drugs, delivery systems, and routes of administration is discussed including factors affecting intraocular bioavailability. Factors such as precorneal fluid drainage, drug binding to tear proteins, systemic drug absorption, corneal factors, melanin binding, and drug metabolism render ocular delivery challenging and are elaborated in this manuscript. Several compartment models are discussed; these are developed in ocular drug delivery to study the pharmacokinetics parameters. There are several transporters present in both anterior and posterior segments of the eye which play a significant role in ocular pharmacokinetics and are summarized briefly. Moreover, several ocular pharmacokinetics animal models and relevant studies are reviewed and discussed in addition to the pharmacokinetics of various ocular formulations.

Parameter uncertainty in biomathematical model described by one-prey two-predator system with mutualism

In this paper, a three-species system consisting of two predators which are in mutualism with each other and preying on the same single prey is considered. Also, the prey and first predator are harvested under optimal conditions. The values of the biological parameters depend on the collection of data from the experts as well as on the nature of the environment in which prey–predator system are considered. So the biological parameters are not precise in reality. This paper presents a different approach to study the prey–predator model with imprecise biological parameters. All the possible equilibrium points are identified and the local as well as global stability criteria under impreciseness are discussed. The possibility of existence of bionomic equilibrium is discussed. The optimal harvesting policy is studied using Pontryagin’s maximum principle. Numerical examples are provided to support the proposed approach.

Topical Formulation of Self-Assembled Antiviral Prodrug Nanomicelles for Targeted Retinal Delivery

Topical drug administration for back of the eye delivery is extremely challenging due to the presence of protection mechanisms and physiological barriers. Self-assembled polymeric nanomicelles have emerged as promising vehicles for drug delivery. Apart from serving as an inert nanocarrier for therapeutic agents, polymeric nanomicelles are known to bypass mononuclear phagocytic system (MPS) and efflux transporters thereby improving drug bioavailability. In this investigation, a highly efficacious biotinylated lipid prodrug of cyclic cidofovir (B-C12-cCDF) was formulated within polymeric nanomicelles as a carrier for targeted retinal delivery. Polymeric nanomicelles were prepared from polyoxyethylene hydrogenated castor oil 40 (HCO-40) and octoxynol 40 (OC-40). In vitro release studies revealed that B-C12-cCDF-loaded nanomicelles released B-C12-cCDF at a faster rate in stimulated tear fluid (STF) in comparison to PBST. MTT and LDH assays demonstrated negligible cytotoxicity of B-C12-cCDF-loaded nanomicelles relative to CDF and B-C12-cCDF in HRPE (human retinal pigment epithelial, D407), HCE-T (human corneal epithelial), and CCL 20.2 (human conjunctival epithelial) cells. Confocal laser scanning microscopy and flow cytometry analyses indicated that B-C12-cCDF-loaded nanomicelles were efficiently internalized into D407 and HCE-T cells in contrast to CDF and B-C12-cCDF. Moreover, little B-C12-cCDF was also observed in the nuclei after 24 h of incubation. Polymeric nanomicelles carrying the transporter targeted prodrug did not produce any cytotoxic effects and were internalized into the cells effectively. Permeability experiments across HCE-T cells further confirmed significant transport of prodrug loaded nanomicelles and their subsequent uptake into D407 cells. These findings indicate that HCO-40/OC-40 based polymeric nanomicelles could become a promising topical delivery system for ocular administration of antiviral agents.

Study of the sign change of exchange bias across the spin reorientation transition in Co(Cr1-x Fe x )2O4 (x = 0.00-0.125)

We present the evolution of novel phenomena of magnetic compensation effect, exchange bias (EB) effect and the field induced anomalies in '[Formula: see text]' substituted multiferroic compound [Formula: see text]. A few percent of '[Formula: see text]' substitution for '[Formula: see text]' in [Formula: see text] results in the reversal of field cooled magnetization under low applied fields below compensation temperature T _comp. Further, increase in the field leads to the spin reorientation transition (T _SR). Signature of EB in a narrow temperature window in the vicinity of T _SR and its sign change across T _SR is observed. Magnitude of EB depends on the amount of compensation and rigidity of the spin reorientation. We also notice the appearance of positive EB below the lock-in transition (T _L). Presence of unidirectional anisotropy developed in the commensurate spin-spiral below T _L could be responsible for the appearance of EB below T _L.

Uptake and bioconversion of stereoisomeric dipeptide prodrugs of ganciclovir by nanoparticulate carriers in corneal epithelial cells

PURPOSE

The objective of this study is to investigate cellular uptake of prodrug-loaded nanoparticle (NP). Another objective is to study bioconversion of stereoisomeric dipeptide prodrugs of ganciclovir (GCV) including L-Val-L-Val-GCV (LLGCV), L-Val-D-Val-GCV (LDGCV) and d-Val-l-Val-GCV (DLGCV) in human corneal epithelial cell (HCEC) model.

METHODS

Poly(_D,L-lactic-co-glycolic acid) (PLGA) NP encapsulating prodrugs of GCV were formulated under a double emulsion method. Fluorescein isothiocyanate isomer-PLGA conjugates were synthesized to fabricate biocompatible fluorescent PLGA NP. Intracellular uptake of FITC-labeled NP was visualized by a fluorescent microscope in HCEC cells.

RESULTS

Fluorescent PLGA NP and non-fluorescent NP display similar hydrodynamic diameter in the range of 115-145 nm with a narrow particle size distribution and zeta potentials around -13 mV. Both NP types showed identical intracellular accumulation in HCEC cells. Maximum uptake (around 60%) was noted at 3 h for NP. Cellular uptake and intracellular accumulation of prodrugs are significantly different among three stereoisomeric dipeptide prodrugs. The microscopic images show that NPs are avidly internalized by HCEC cells and distributed throughout the cytoplasm instead of being localized on the cell surface. Following cellular uptake, prodrugs released from NP gradually bioreversed into parent drug GCV. LLGCV showed the highest degradation rate, followed by LDGCV and DLGCV.

CONCLUSION

LLGCV, LDGCV and DLGCV released from NP exhibited superior uptake and bioreversion in corneal cells.

Recent perspectives on the delivery of biologics to back of the eye

INTRODUCTION

Biologics are generally macromolecules, large in size with poor stability in biological environments. Delivery of biologics to tissues at the back of the eye remains a challenge. To overcome these challenges and treat posterior ocular diseases, several novel approaches have been developed. Nanotechnology-based delivery systems, like drug encapsulation technology, macromolecule implants and gene delivery are under investigation. We provide an overview of emerging technologies for biologics delivery to back of the eye tissues. Moreover, new biologic drugs currently in clinical trials for ocular neovascular diseases have been discussed. Areas covered: Anatomy of the eye, posterior segment disease and diagnosis, barriers to biologic delivery, ocular pharmacokinetic, novel biologic delivery system Expert opinion: Anti-VEGF therapy represents a significant advance in developing biologics for the treatment of ocular neovascular diseases. Various strategies for biologic delivery to posterior ocular tissues are under development with some in early or late stages of clinical trials. Despite significant progress in the delivery of biologics, there is unmet need to develop sustained delivery of biologics with nearly zero-order release kinetics to the back of the eye tissues. In addition, elevated intraocular pressure associated with frequent intravitreal injections of macromolecules is another concern that needs to be addressed.

Circumvention of P-gp and MRP2 mediated efflux of lopinavir by a histidine based dipeptide prodrug

PURPOSE

This study was aimed to develop a novel Histidine-Leucine-Lopinavir (His-Leu-LPV) dipeptide prodrug and evaluate its potential for circumvention of P-gp and MRP2-mediated efflux of lopinavir (LPV) indicated for HIV-1 infection.

METHODS

His-Leu-LPV was synthesized following esterification of hydroxyl group of LPV and was identified by (1)H NMR and LCMS/MS techniques. Aqueous solubility, stability and cell cytotoxicity of prodrug was determined. Uptake and permeability studies were carried out using P-gp (MDCK-MDR1) and MRP2 (MDCK-MRP2) transfected cell lines. To further delineate prodrug uptake, prodrug interaction with influx transporters (PepT1 and PHT1) was determined. Enzymatic hydrolysis and reconversion of His-Leu-LPV to LPV was examined using Caco-2 cell homogenates.

RESULTS

Aqueous solubility generated by the prodrug was markedly higher relative to unmodified LPV. Importantly, His-Leu-LPV displayed significantly lower affinity towards P-gp and MRP2 as evident from higher uptake and transport rates. [3H]-GlySar and [3H]-l-His uptake receded to approximately 30% in the presence of His-Leu-LPV supporting the PepT1/PHT1 mediated uptake process. A steady regeneration of LPV and Leu-LPV in Caco-2 cell homogenates indicated His-Leu-LPV undergoes both esterase and peptidase-mediated hydrolysis.

CONCLUSION

Histidine based dipeptide prodrug approach can be an alternative strategy to improve LPV absorption across poorly permeable intestinal barrier.

Transporter effects on cell permeability in drug delivery

INTRODUCTION

The role of drug transporters as one of the determinants of cellular drug permeability has become increasingly evident. Despite the lipophilicity of a drug molecule as rate-limiting factor for passive diffusion across biological membranes, carrier-mediated and active transport have gained attention over the years. A better understanding of the effects and roles of these influx transporters towards transmembrane permeability of a drug molecule need to be delineated for drug development and delivery. Areas covered: This review focuses on findings relative to role of transporters in drug absorption and bioavailability. Particularly the areas demanding further research have been emphasized. This review will also highlight various transporters expressed on vital organs and their effects on drug pharmacokinetics. Expert opinion: Significant efforts have been devoted to understand the role of transporters, their iterative interplay with metabolizing enzymes through molecular enzymology, binding and structure-activity relationship studies. A few assays such as parallel artificial membrane permeation assay (PAMPA) have been developed to analyze drug transport across phospholipid membranes. Although large web-accessible databases on tissue selective expression profiles at transcriptomic as well as proteomic are available, there is a need to collocate the scattered literature on the role of transporters in drug development and delivery.

Stability and Bionomic Analysis of Fuzzy Prey-Predator Harvesting Model in Presence of Toxicity: A Dynamic Approach

This paper deals with a prey-predator model in which both the species are infected by some toxicants which are released by some other species or source with fuzzy biological parameters. The application of fuzzy differential equation in the modeling of prey-predator populations with the effect of toxicants is presented. The dynamical behavior and harvesting of the fuzzy exploited system are studied by using the utility function method. Sufficient conditions for the local stability of the positive equilibrium are obtained by analyzing the characteristic equation. Furthermore, the possibility of the existence of bionomic equilibrium is studied under imprecise biological parameters. The study of the presence of toxic substance and harvesting in the modeling system can have significant impact on the existence of both the species, which is in line with reality. Numerical simulation results are presented to validate the theoretical analysis.

Long-term in vitro maintenance of clonal abundance and leukaemia-initiating potential in acute lymphoblastic leukaemia

Lack of suitable in vitro culture conditions for primary acute lymphoblastic leukaemia (ALL) cells severely impairs their experimental accessibility and the testing of new drugs on cell material reflecting clonal heterogeneity in patients. We show that Nestin-positive human mesenchymal stem cells (MSCs) support expansion of a range of biologically and clinically distinct patient-derived ALL samples. Adherent ALL cells showed an increased accumulation in the S phase of the cell cycle and diminished apoptosis when compared with cells in the suspension fraction. Moreover, surface expression of adhesion molecules CD34, CDH2 and CD10 increased several fold. Approximately 20% of the ALL cells were in G0 phase of the cell cycle, suggesting that MSCs may support quiescent ALL cells. Cellular barcoding demonstrated long-term preservation of clonal abundance. Expansion of ALL cells for >3 months compromised neither feeder dependence nor cancer initiating ability as judged by their engraftment potential in immunocompromised mice. Finally, we demonstrate the suitability of this co-culture approach for the investigation of drug combinations with luciferase-expressing primograft ALL cells. Taken together, we have developed a preclinical platform with patient-derived material that will facilitate the development of clinically effective combination therapies for ALL.

Nanoparticle-Based Topical Ophthalmic Gel Formulation for Sustained Release of Hydrocortisone Butyrate

This study was conducted to develop formulations of hydrocortisone butyrate (HB)-loaded poly(D,L-lactic-co-glycolic acid) nanoparticles (PLGA NP) suspended in thermosensitive gel to improve ocular bioavailability of HB for the treatment of bacterial corneal keratitis. PLGA NP with different surfactants such as polyvinyl alcohol (PVA), pluronic F-108, and chitosan were prepared using oil-in-water (O/W) emulsion evaporation technique. NP were characterized with respect to particle size, entrapment efficiency, polydispersity, drug loading, surface morphology, zeta potential, and crystallinity. In vitro release of HB from NP showed a biphasic release pattern with an initial burst phase followed by a sustained phase. Such burst effect was completely eliminated when nanoparticles were suspended in thermosensitive gels and zero-order release kinetics was observed. In HCEC cell line, chitosan-emulsified NP showed the highest cellular uptake efficiency over PVA- and pluronic-emulsified NP (59.09 ± 6.21%, 55.74 ± 6.26%, and 62.54 ± 3.30%, respectively) after 4 h. However, chitosan-emulsified NP indicated significant cytotoxicity of 200 and 500 μg/mL after 48 h, while PVA- and pluronic-emulsified NP exhibited no significant cytotoxicity. PLGA NP dispersed in thermosensitive gels can be considered as a promising drug delivery system for the treatment of anterior eye diseases.

Optimization of novel pentablock copolymer based composite formulation for sustained delivery of peptide/protein in the treatment of ocular diseases

This manuscript is focussed on the development of pentablock (PB) copolymer based sustained release formulation for the treatment of posterior segment ocular diseases. We have successfully synthesised biodegradable and biocompatible PB copolymers for the preparation of nanoparticles (NPs) and thermosensitive gel. Achieving high drug loading with hydrophilic biotherapeutics (peptides/proteins) is a challenging task. Moreover, small intravitreal injection volume (≤100 μL) requires high loading to develop a long term (six months) sustained release formulation. We have successfully investigated various formulation parameters to achieve maximum peptide/protein (octreotide, insulin, lysozyme, IgG-Fab, IgG, and catalase) loading in PB NPs. Improvement in drug loading can facilitate delivery of larger doses of therapeutic proteins via limited injection volume. A composite formulation comprised of NPs in gel system exhibited sustained release (without burst effect) of peptides and proteins, may serve as a platform technology for the treatment of posterior segment ocular diseases.

Novel strategies for the treatment of diabetic macular edema

Macular edema such as diabetic macular edema (DME) and diabetic retinopathy are devastating back-of-the-eye retinal diseases leading to loss of vision. This area is receiving considerable medical attention. Posterior ocular diseases are challenging to treat due to complex ocular physiology and barrier properties. Major ocular barriers are static (corneal epithelium, corneal stroma, and blood-aqueous barrier) and dynamic barriers (blood-retinal barrier, conjunctival blood flow, lymph flow, and tear drainage). Moreover, metabolic barriers impede posterior ocular drug delivery and treatment. To overcome such barriers and treat back-of-the-eye diseases, several strategies have been recently developed which include vitreal drainage, laser photocoagulation and treatment with biologics and/or small molecule drugs. In this article, we have provided an overview of several emerging novel strategies including nanotechnology based drug delivery approach for posterior ocular drug delivery and treatment with an emphasis on DME.

Low temperature neutron diffraction studies on Co(Cr1−xFex)2O4 (x = 0.05 and 0.075)

We report the magnetic structures of an Fe substituted cobalt chromite system, Co(Cr_1−xFe_x)₂O₄ (x = 0.05 and 0.075), determined from the analysis of temperature dependent neutron diffraction measurements.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.