Efficient Design to Monitor the Site-specific Sustained Release of a Non-Emissive Anticancer Drug.

A pH-responsive smart nanocarrier with significant components was synthesized by conjugating the non-emissive anticancer drug methyl orange and polyethylene glycol derived folate moiety to the backbone of polynorbornene. Complete synthesis procedure and characterization methods of three monomers included in the work: norbornene-derived Chlorambucil (Monomer 1), norbornene grafted with polyethylene glycol, and folic acid (Monomer 2) and norbornene attached methyl orange (Monomer 3) connected to the norbornene backbone through ester linkage were clearly discussed. Finally, the random copolymer CHO PEG FOL METH was synthesized by ring-opening metathesis polymerization (ROMP) using Grubbs' second-generation catalyst. Advanced polymer chromatography (APC) was used to find the final polymer's molecular weight and polydispersity index (PDI). Dynamic light scattering, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were utilized to explore the prodrug's size and morphology. Release experiments of the anticancer drug, Chlorambucil and the coloring agent, methyl orange, were performed at different pH and time. Cell viability assay was carried out for determining the rate of survived cells, followed by the treatment of our final polymer named CHO PEG FOL METH.

Hetero-Trifunctional Malonate-Based Nanotheranostic System for Targeted Breast Cancer Therapy.

Designing multifunctional linkers is crucial for tricomponent theranostic targeted nanomedicine development as they are essential to enrich polymeric systems with different functional moieties. Herein, we have obtained a hetero-trifunctional linker from malonic acid and demonstrated its implication as an amphiphilic targeted nanotheranostic system (CB DX UN PG FL). We synthesized it with varying hydrophilic segment to fine-tune the hydrophobic/hydrophilic ratio to optimize its self-assembly. pH-responsive hydrazone-linked doxorubicin was conjugated to the backbone (UN PG FL) containing folate as a targeting ligand. Cobalt carbonyl complex was used for T2-weighted magnetic resonance imaging (MRI). Electron micrographs of optimized molecule CB DX UN PG(4 kDa)FL in an aqueous system have demonstrated about 50-60 nm-sized uniform micelles. The relaxivity study and the one-dimensional (1D) imaging experiments clearly revealed the effect of the nanotheranostics system on transverse relaxation (T2) of water molecules, which validated the system as a T2-weighted MRI contrast agent. The detailed in vitro biological studies validated the targeted delivery and anticancer potential of CB DX UN PG(4 kDa)FL. Combining the data on transverse relaxation, folate mediated uptake, and anticancer activity, the designed molecule will have a significant impact on the development of targeted theranostic.

Analysis of long-term culture properties and pluripotent character of two sibling human embryonic stem cell lines derived from discarded embryos.

We had earlier reported the derivation and characterization of two new sibling human embryonic stem cell lines BJNhem19 and BJNhem20, from discarded grade III embryos of Indian origin. We report here the characteristics of the two sibling cell lines after long-term continuous culture for over 2 yr during which they have been passaged over 200 times. We show that both cell lines adapt well to culture on various mouse and human feeders as well as in feeder-free conditions. The cells show normal diploid karyotype and continue to express all pluripotency markers. Both cell lines differentiate to derivatives of all three germ layers in vitro. However as reported earlier, BJNhem19 is unable to generate teratomas in nude or SCID mice or differentiate to beating cardiomyocytes when tested over several passages during long-term stable culture. On the other hand, the cardiac differentiation capacity of BJNhem20 is greatly increased, and it can generate beating cardiomyocytes that proliferate when isolated and cultured further. In conclusion, the two cell lines have maintained a stable phenotype for over 2 yr and are indeed immortal. Their derivation from grade III embryos does not seem to have any adverse effect on their long-term phenotype. The cells can be obtained for research purposes from the UK Stem Cell Bank and from the authors.

Derivation and characterization of two sibling human embryonic stem cell lines from discarded grade III embryos.

Human embryonic stem (hES) cells are a valuable tool for studying human development in addition to their potential applications in regenerative medicine and drug discovery. The role of genetic background and epigenetic influences in development as well as in response to external influences such as drugs and therapies is well recognized. The great ethnic diversity in the Indian subcontinent translates to interindividual variability in drug response and disease susceptibility. For these reasons, new hES cell lines representing Indian genetic diversity will be valuable in studies of tissue-differentiation, cellular-function and for aspects of characterization of responses to drugs. We have derived two new hES cell lines, BJNhem19 and BJNhem20 from the inner cell mass (ICM) of discarded grade III human embryos that were not suitable for in vitro fertility treatment. Human leukocyte antigen (HLA) isotype analysis shows that they are genetically distinct from existing hES cell lines. Short tandem repeat (STR) analysis shows that the two cell lines are derived from sibling embryos. These cell lines show an undifferentiated phenotype in culture for more than 65 passages, show normal karyotype and express pluripotency markers such as TRA-1-60, TRA-1-81, stage-specific embryonic antigen-4 (SSEA-4), alkaline phosphatase, DNMT3B, GABRB3, GDF3, OCT4, NANOG, SOX2, TERF1, TDGF, LEFTA, THY1, and REX1. While both cell lines can differentiate into derivatives of all three germ layers in vitro, only BJNhem20 can form teratomas when transplanted into mice. We observe an increased frequency of cardiomyocyte differentiation from BJNhem20 embryoid bodies in feeder-free cultures upon induction with DMSO. Cardiomyocytes purified from such cultures survive and show rhythmic contractions for several weeks in culture. These hES cell lines have been accepted for deposit in the U.K. Stem Cell Bank and will be a useful resource for the international stem cell community.

Human BCAS3 expression in embryonic stem cells and vascular precursors suggests a role in human embryogenesis and tumor angiogenesis.

Cancer is often associated with multiple and progressive genetic alterations in genes that are important for normal development. BCAS3 (Breast Cancer Amplified Sequence 3) is a gene of unknown function on human chromosome 17q23, a region associated with breakpoints of several neoplasms. The normal expression pattern of BCAS3 has not been studied, though it is implicated in breast cancer progression. Rudhira, a murine WD40 domain protein that is 98% identical to BCAS3 is expressed in embryonic stem (ES) cells, erythropoiesis and angiogenesis. This suggests that BCAS3 expression also may not be restricted to mammary tissue and may have important roles in other normal as well as malignant tissues. We show that BCAS3 is also expressed in human ES cells and during their differentiation into blood vascular precursors. We find that BCAS3 is aberrantly expressed in malignant human brain lesions. In glioblastoma, hemangiopericytoma and brain abscess we note high levels of BCAS3 expression in tumor cells and some blood vessels. BCAS3 may be associated with multiple cancerous and rapidly proliferating cells and hence the expression, function and regulation of this gene merits further investigation. We suggest that BCAS3 is mis-expressed in brain tumors and could serve as a human ES cell and tumor marker.