Amit Singh

PureTech Health · Formulations

Nanomedicine is a rapidly emerging field with several breakthroughs in the therapeutic drug delivery application. The unique properties of the nanoscale delivery systems offer huge advantages to their payload such as solubilization, increased bioavailability, and improved pharmacokinetics with an overall goal of enhanced therapeutic index. Nanomedi...

Impact of nanotechnology for anticancer therapy has been projected with great promises for the past two decades and has been followed with thousands of research publications and preclinical success stories, but relatively poor clinical outcomes. Nanoparticles have served as excellent delivery vectors for drugs that have poor biological stability an...

The purpose of this review is to discuss the challenges associated with the development of nanoparticle-based quality drug products in adhering to the principles of quality by design (QbD) and defining appropriate quality parameters towards successful product development. With the advent of nanotechnology into the pharmaceutical field, the novel fi...

The natural specificity of bacteriophages toward their hosts represents great potential for the development of platforms for the capture and detection of bacterial pathogens. Whole phage can carry reporter genes to alter the phenotype of the target pathogen. Phage can also act as staining agents or the progeny of the infection process can be detect...

Introduction: As one of the most aggressive cancers worldwide, pancreatic cancer is associated with an extremely poor prognosis. The pancreatic tumor microenvironment consists of cancer cells and other tumor associated cells. Cross-talk between these different cell types through various signaling molecules results in the development of a more aggre...

Translation of nanoparticle-based therapeutics from preclinical to clinical stage has seen slow progress compared with their small molecules counterparts primarily due to lack of suitable technologies that can map the high-throughput combinatorial chemistry-based approach of molecule design. Our improved understanding of materials chemistry and pro...

Therapies targeting epigenetic changes for cancer treatment are in Phase I/II trials; however, all of these target only nuclear DNA. Emerging evidence suggests presence of methylation marks on mitochondrial DNA (mtDNA); but their contribution in cancer is unidentified. Expression of genes encoded on mtDNA are altered in cancer cells, along with inc...

Stimuli-responsive nano-carrier systems have been pursued with great interest due to their advantages such as controlled drug release, improved pharmacokinetics and pharmacodynamics, and reduced side effects of the drugs. These nano-carriers have potential to accumulate effectively into the tumor due to “enhanced permeability and retention” (EPR) e...

Statement of significance: Lung cancer remains one of the leading killers in the United States and around the world. Platinum agents, including cisplatin, are the first line treatment in lung cancer, including non-small cell lung cancer (NSCLC), which is the predominant form of lung cancer. In this study, we have evaluated Mad2 cell-cycle checkpoi...

Background: The present study focuses on biodistribution profile and pharmacokinetic parameters of EGFR-targeted chitosan nanoparticles (TG CS nanoparticles) for siRNA/cisplatin combination therapy of lung cancer. Material & methods: Mad2 siRNA was encapsulated in EGFR targeted and nontargeted (NTG) CS nanoparticles by electrostatic interaction....

Development of efficient and versatile drug delivery platforms to overcome the physical and biological challenges in cancer therapeutics is an area of great interest and novel materials for such application are actively sought for such applications. Recent strides in polymer science has led to a combinatorial approach for generating a library of ma...

Cluster of differentiation-44 (CD44) is a ubiquitously present glycoprotein on the surface of mammalian cells that plays a significant role in a number of biological functions. Since the discovery that the receptor is over-expressed in a variety of solid tumors, such as pancreatic, breast and lung cancer, many studies have focused on methods for ta...

Synthesis of EGFR peptide-modified DSPE-PEG-MAL and its incorporation into liposomes. Abbreviations: 3-BPA, 3-bromopyruvate; DSPC, 1,2–distearoyl-sn-glycero-3-phosphocholine; DSPE, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine; EGFR, epidermal growth factor receptor; MAL, maleimide; PEG, polyethylene glycol.

RT-PCR analysis of glycolytic markers in two-dimensional SKOV-3 ovarian cancer cell culture and in three-dimensional spheroids. Notes: The bands run on the 2% agarose E-gel image show relative expression of (A) GLUT I and HK2 for day 3 samples, (B) PKM2 and LDHA for day 3 samples, (C) GLUT I and HK2 for day 5 samples, and (D) PKM2 and LDHA for day...

Comparative analysis of glycolytic marker expression profiles in a two-dimensional SKOV-3 ovarian cancer cell culture and in three-dimensional spheroids. Notes: mRNA expression levels of each gene were normalized to the respective β-actin band intensity. The values are reported as the mean ± standard deviation calculated for n=3. The samples corres...

Transmission electron microscopic images of 3-bromopyruvate-loaded liposomes revealing spherical morphology and size. Notes: (A) Non-targeted liposomes and (B) EGFR-targeted liposomes. Original magnification of the transmission electron micrographs was 10,000× with a scale bar of 500 nm. Abbreviations: EGFR, epidermal growth factor receptor; HV, hi...

Background: The objective of this study was to evaluate the expression levels of glycolytic markers, especially hexokinase-2 (HK2), using a three-dimensional multicellular spheroid model of human ovarian adenocarcinoma (SKOV-3) cells and to develop an epidermal growth factor receptor-targeted liposomal formulation for improving inhibition of HK2 a...

It is clear that exosomes (endosome derived vesicles) serve important roles in cellular communication both locally and distally and that the exosomal process is abnormal in cancer. Cancer cells are not malicious cells; they are cells that represent 'survival of the fittest' at its finest. All of the mutations, abnormalities, and phenomenal adaptati...

In recent years, mitochondrial medicine has emerged as a new discipline resting at the intersection of mitochondrial biology, pathology, and pharmaceutics. The central role of mitochondria in critical cellular processes such as metabolism and apoptosis has placed mitochondria at the forefront of cell science. Advances in mitochondrial biology have...

Platinum-based therapies are the first line treatments for most types of cancer including ovarian cancer. However, their use is associated with dose-limiting toxicities and resistance. We report initial translational studies of a theranostic nanoemulsion loaded with a cisplatin derivative, myrisplatin and pro-apoptotic agent, C6-ceramide. The surfa...

Development of multidrug resistance (MDR) is an almost universal phenomenon in patients with ovarian cancer, and this severely limits the ultimate success of chemotherapy in the clinic. Overexpression of the MDR1 gene and corresponding P-glycoprotein (Pgp) is one of the best known MDR mechanisms. MDR1 siRNA based strategies were proposed to circumv...

Approaches for the synthesis of biomaterials to facilitate the delivery of "biologics" is a major area of research in cancer therapy. Here we designed and characterized a hyaluronic acid (HA) based self-assembling nanoparticles that can target CD44 receptors overexpressed on multidrug resistance (MDR) ovarian cancer. The nanoparticle system is comp...

This review discusses the challenges associated with drug delivery and benefits of employing nanosystems in the delivery of small and macromolecular drugs. Poor biopharmaceutical characteristics of drug and biological barriers in the body affect the drug molecules reaching the intended disease site. For instance, solubility and permeability of a dr...

RNA interference has emerged as a powerful strategy in cancer therapy because it allows silencing of specific genes associated with tumor progression and resistance. Mad2 is an essential mitotic checkpoint component required for accurate chromosome segregation during mitosis, and its complete abolition leads to cell death. We have developed an epid...

The American Cancer Society projects 1,660,290 new cases and 580,350 deaths from cancer in the United States in 2013, accounting for one in every four human illness-related deaths. Poor therapeutic outcome of cancer can be largely related to lack of technologies to diagnose the disease in its early stage of development, where the tumor is still con...

There have been significant advances in our understanding of cancer as a disease at the molecular level. Combined with improved diagnostic systems, the concept of personalized medicine was introduced where therapy for every patient can be customized according to their disease profile. The nanotechnology approach for formulation design and the adven...

Objective: Ovarian cancer is a highly lethal disease in which the majority of patients eventually demonstrate multidrug resistance. Develop a novel active targeted theranostic nanomedicine designed to overcome drug efflux mechanisms, using a Generally Regarded As Safe (GRAS) grade nanoemulsion (NE) as a clinically relevant platform. Materials and...

Introduction: Cancer cells acclimatize to the harsh tumor microenvironment by altering cellular metabolism in favor of aerobic glycolysis. This process provides a source of energy and also generates essential components for macromolecular biosynthesis, which enables cellular survival. As the dependence of cancer cells on glycolysis affects tumorig...

Inflammation is an immune response that marks several pathophysiological conditions in our body. Though adaptive immune cells play a major role in the progression of the disease, components of innate immune system, mainly monocytes and macrophages play the central role in onset of inflammation. Tissue-associated macrophages are widely distributed i...

Platinum-based chemotherapy is the treatment of choice for malignant epithelial ovarian cancers, but generalized toxicity and platinum resistance limits its use. Theranostic nanoemulsion with a novel platinum prodrug, myrisplatin, and the pro-apoptotic agent, C6-ceramide, were designed to overcome these limitations. The nanoemulsions, including one...

Pancreatic adenocarcinoma is one of the most dreaded cancers with very low survival rate and poor prognosis to the existing frontline chemotherapeutic drugs. Gene therapy in combination with a cytotoxic agent could be a promising approach to circumvent the limitations of previously attempted therapeutic interventions. We have developed a redox-resp...

Nanoemulsion dosage form serves as a vehicle for the delivery of active pharmaceutical ingredients and has attracted great attention in drug delivery and pharmacotherapy. In particular, nanoemulsions act as an excellent vehicle for poorly aqueous soluble drugs, which are otherwise difficult to formulate in conventional dosage forms. Nanoemulsions a...

The in vitro evaluation of chemotherapeutic delivery systems is essential as a prediction of in vivo chemotherapeutic effi cacy. Generally, the in vitro therapeutic effi cacy of chemotherapeutic agents is evaluated by using cellular monolayers cultured in a fl at-bottomed plastic culture dish prior to expensive and arduous in vivo studies. Despite...

Aminoglycosides are broad-spectrum antibiotics that are used for the treatment of severe Gram-negative and Gram-positive bacterial infections. While bactericidal effects of aminoglycosides are due to binding to the 30S subunit of the bacterial ribosome, aminoglycosides can affect protein synthesis, intracellular calcium levels and levels of reactiv...

This chapter outlines the challenges associated with effective drug and gene delivery to tumors, and strategic approaches to augment the efficacy of anticancer agents by utilizing multifunctional nanosystems. Extensive knowledge of the chemistry of biomaterials, surface engineering, and the ability to manipulate materials at the nanoscale, coupled...

We present a novel phage receptor binding protein-based magnetic separation and pre-enrichment method as an alternative to the immunomagnetic separation methods by replacing antibodies with bacteriophage receptor binding proteins (RBPs). We couple the proposed RBP-based magnetic separation with real time PCR for rapid, sensitive and specific detect...

Most Campylobacter bacteriophages isolated to date have long contractile tails and belong to the family Myoviridae. Based on their morphology, genome size and endonuclease restriction profile, Campylobacter phages were originally divided into three groups. The recent genome sequencing of seven virulent campylophages reveal further details of the re...

Bacteriophage based technology has gained interest in developing pathogen detection platforms for biosensing applications. In this study, P22 phage tail spike proteins (TSPs) have been immobilized on Si surfaces for optimized capture of host Salmonella enteric serovar Typhimurium. It was then demonstrated that roughening of the Si surface before th...

Foodborne diseases are a major health concern that can have severe impact on society and can add tremendous financial burden to our health care systems. Rapid early detection of food contamination is therefore relevant for the containment of food-borne pathogens. Conventional pathogen detection methods, such as microbiological and biochemical ident...

Metal nanoparticles have fascinated scientists since the middle ages due to their vibrant colors and have been used as colorant in glass windows and pottery. The colloidal chemistry resurged to popularity in the 1850s when Faraday first synthesized pure gold sol and called it "activated gold". Since then, scientists across the world have tried to u...

A review of activities involving the development of large arrays of nanomechanical resonators is presented. This review includes demonstration of the use of these arrays for the detection of biological targets. Both top-down and bottom-up approaches to the realization of such arrays were developed. Using a top-down approach, a nanomachining method...

Rapid and specific detection of pathogenic bacteria is important for the proper treatment, containment and prevention of human, animal and plant diseases. Identifying unique biological probes to achieve a high degree of specificity and minimize false positives has therefore garnered much interest in recent years. Bacteriophages are obligate intrace...

Nanoimprint lithography was used to fabricate arrays of SiCN nanoscale resonators for biological analysis applications. A bilayer resist consisting of PMMA 495/LOR 3A allowed high fabrication yields for reso-nators of widths ranging from 120 to 300 nm, thicknesses of 40 and 70 nm, and a length of 14 μm. To our knowledge, these 120 nm resonators are...

Bacteriophages offer interesting alternatives to antibodies for the specific capture and detection of pathogenic bacteria onto biosensing surfaces. Procedures for the optimal chemical immobilization of lytic bacteriophages onto surfaces are presented. More specifically, the removal of lysate contaminants from bacteriophage suspensions by size exclu...

Ovarian cancer is a debilitating disease, which needs multi-pronged approach of targeted drug delivery and enhanced efficacy with the use of combination therapeutics. In this study, we have examined the anticancer activity of PIK75 incorporated in surface functionalized nanoemulsions for targeted delivery to SKOV-3 cells. A pro-apoptotic molecule C...

Mercury is a serious environmental pollutant known to have detrimental health effects in all life forms. Here, we report the use of biologically synthesized aqueous gold nanotriangles for sensitive and selective optical detection of femto-molar levels of mercury ions by exploiting the high amalgamation tendency of mercury metal towards gold. Aqueou...

Biogenic gold nanotriangles have been used in this study to understand their cytotoxicity and biocompatibility in animal cells. These gold nanotriangles were synthesized using the leaf extract of the lemon grass (Cymbopogan flexuosus) plant. Cancerous as well as non-cancerous cells were used to study their dose dependent viability on exposure to th...

Campylobacter jejuni continues to be the leading cause of bacterial food-borne illness worldwide, so improvements to current methods used for bacterial detection and disease prevention are needed. We describe here the genome and proteome of C. jejuni bacteriophage NCTC 12673 and the exploitation of its receptor-binding protein for specific bacteria...

Campylobacter jejuni is found in the intestines of poultry, cattle, swine, wild birds and pet animals and is the major cause of foodborne gastroenteritis in developed countries. We report the use of the receptor binding protein (RBP) of Campylobacter bacteriophage NCTC 12673 for the specific capture of Campylobacter jejuni bacteria using RBP-deriva...

We report a novel design for the intermediary layer of surface plasmon resonance (SPR) devices that use high refractive index and high-transmittance zinc oxide (ZnO) dielectric layers to enhance the signal quality and improve the full width at half-maximum (FWHM) of the reflectivity curve. We optimized the design of ZnO thin films using different s...

A bioassay platform using T4 bacteriophage (T4) as the specific receptor and surface plasmon resonance (SPR) as the transduction technique has been developed for the detection of Escherichia coli K12 bacteria. The T4 phages have been covalently immobilized onto gold surfaces using a self-assembled monolayer of dithiobis(succinimidyl propionate) (DT...

We report the use of genetically engineered tailspike proteins (TSPs) from the P22 bacteriophage for the sensitive and selective detection of Salmonella enterica serovar Typhimurium. High yields of two mutant TSPs, one with an N-terminal cysteine (N-Cys) and another with a C-terminal cysteine (C-Cys), have been obtained using recombinant protein ex...

Techniques for the chemical attachment of wild-type bacteriophages onto gold surfaces and the subsequent capture of their host bacteria have been developed. The surfaces were modified with sugars (dextrose and sucrose) as well as amino acids (histidine and cysteine) to facilitate such attachment. Non-specific attachment was prevented by using bovin...

The paper presents a time-dependent study of shape-dependent preferential complexation of gold nanoparticles to the octadecyl amine (ODA) monolayers at the air-water interface. Room temperature reduction of chloroaurate ions using lemon grass leaf extract yields a mixture of spherical and triangular nanoparticles, which were used for this study. Th...

Spider silk is being viewed with interest by materials scientists due to its excellent resilience and mechanical properties. In this paper we show that spider silk is an excellent scaffold for the one-step synthesis and assembly of gold nanoparticles. Formation of a gold nanoparticle-spider-silk bioconjugate material is accomplished by simple react...

Metal nanoparticles are interesting building blocks for realizing films for a number of applications that include bio- and chemical sensing. To date, spherical metal nanoparticles have been used to generate functional electrical coatings. In this paper we demonstrate the synthesis of electrically conductive coatings using biologically prepared gold...

In this paper, we demonstrate the effect of halide ions on the formation of biogenically prepared gold nanotriangles using the leaf extract of lemongrass (Cymbopogon flexuosus) plant. We have also studied the effect of halide ions on the morphology of biogenic nanotriangles. It has been shown that iodide ions have a greater propensity to transform...

The optoelectronic and physicochemical properties of nanoscale matter are a strong function of particle size. Nanoparticle shape also contributes significantly to modulating their electronic properties. Several shapes ranging from rods to wires to plates to teardrop structures may be obtained by chemical methods; triangular nanoparticles have been...

We report in this study the largest surface capture density of E Coli using the wild-type T4 bacteriophage; whereby higher surface capture density can enable higher sensitivities for surface-based biosensors. This was possible due to our purification of the phage lysate, which significantly improved phage surface density, achieving maximum (jamming...

We report the high-yield fabrication of SiCN doubly-clamped nanomechanical resonator arrays for the specific detection of proteins. As a proof of concept, specific detection of Protein A has been demonstrated. The resonant frequencies of the individual resonators were determined using optical interferometry. The bare resonators displayed resonance...