Re: GENE THERAPY IN CHINA-What i found out

[Guest guest]

Thanks for your post. Here is some additional information about

nanoparticles. The links at the end of this piece provide more information.

Nanoparticles May Play a Role in Inhibiting the Multidrug Resistance in

Chemotherapy

(Newswire Today) — Honolulu HI, United States, 2006-07-06 - New research by

suggests that nanoparticle surface chemistry and size as well as the unique

properties of the magnetic nanoparticles themselves may contribute to a

synergistic enhanced effect of drug uptake of cancer cells.

Multidrug resistance, the principal mechanism by which many cancers develop

resistance to chemotherapy drugs, is a major factor in the failure of many

forms of chemotherapy. New research by Chinese scientists suggests that

nanoparticle surface chemistry and size as well as the unique properties of the

magnetic nanoparticles themselves may contribute to a synergistic enhanced

effect of

drug uptake of targeted cancer cells. These findings could result in promising

biomedical applications for cancer therapy.

Professor Xuemei Wang from the the State Key Laboratory of Bioelectronics

(Chien-Shiung Wu Laboratory) in Nanjing, PR China, together with several of her

colleagues from Southeast University, recently published a paper titled

" Synergistic enhancement effect of magnetic nanoparticles on anticancer drug

accumulation in cancer cells " in the June 26, 2006 online issue of

Nanotechnology.

In it, the researchers describe their investigation of the synergistic effect

of three kinds of magnetic nanoparticles, nano Fe3O4, Ni and Fe2O3, on the

drug uptake of anticancer drug daunorubicin in leukemia K562 cells.

They show how Fe3O4 nanoparticles could remarkably enhance the uptake or

diffusion efficiency of anticancer drugs into target cancer cells (especially

drug

resistance cancer cells). If Fe3O4 nanoparticles, which are biocompatible and

very stable, are fixed at the ailing area by using external magnetic field

during the tumor treatment, the chemotherapy effect could be considerably

enhanced by combination of the application of the new magnetic nanoparticles in

drug

delivery systems for achieving the targeting and controlled drug release.

" Our results illustrate that the presence of magnetic nanoparticles could

facilitate the drug accumulation of daunorubicin inside leukemia cells and the

enhancement effect of nano Fe3O4 is much stronger than that of the other two

magnetic nanoparticles " Wang explains the findings to Nanowerk. " These

observations are consistent with the results of our recent biological

experimental

studies, which indicates that the presence of Fe3O4 nanoparticles could

apparently

inhibit the growth of the respective leukemia cells (Interestingly, the Fe3O4

nanoparticle itself could also inhibit the cell growth somehow); especially,

when treated the target cells by anticancer drug daunorubicin together with

Fe3O4 nanoparticles, the growth of leukemia cells could be much more remarkably

inhibited than that with only daunorubicin or other nanoparticles. Since these

three kinds of nanoparticles were all capped with the tetraheptylammonium, our

observations suggest that both the size and the unique properties of magnetic

nanoparticles themselves may contribute to the synergistic enhanced effect of

the drug uptake of targeted cancer cells. "

The magnetic targeting offers a unique opportunity to treat tumors without

systemic toxicity. It is known that the cure efficiency of cancer chemotherapy

depends not only on the anticancer drug itself but also on how it is delivered

to its targets. As already reported in some literature, it has been observed

that the magnetic particles can be targeted and concentrated in some tumor

tissue at significantly high level.

" Our observations indicate that magnetic nanoparticles with different size

and surface chemistry have different ability to enter target cells and thus the

relative efficiency of the drug delivery systems by the conjugation of drugs

with nanoparticles will be critically dependent upon nanoparticle surface

chemistry and size of the functionalized nanoparticles " says Wang.

" Based on these observations, our future research with regard to cancer

therapy may focus on the relative mechanisms of new magnetic nanoparticles " Wang

describes a possible direction for her group's future research. " Magnetic

nanomaterials are especially promising for the early diagnosis of some cancers

and

for efficiently targeting chemotherapy.

By Berger, Copyright 2006 Nanowerk LLC. All rights reserved.

Agency / Source:

# # #

[Guest guest]

How about blood cancers that don't involve solid tumors? Would Gendocine

work with those?

Andy

Re: GENE THERAPY IN CHINA-What i found out

> For what its worth...

> I looked into this 2 years ago. The process seems to work if the cancer

> is detected early and tumors haven't matured. It has the same problems

> asdendretic vaccines in that if the tumor size passes the threshold for

> the capacity of the immune system dendretic vaccines/adenoviral processes

> seems to have some impact on the markers (average of 6 months for

> dendretic vaccines) but tumor growth doesn't seem to be impugned.

>

> One of the problems with the adenoviral (Gendocine) process is the

> inability to deliver a big enough payload to the tumor. U of Cal Santa

> Barbara group developed a honeycomb molecule that has the capacity to

> carry larger quantity of virus but it won't be ready for " years " ...

> Introgen is switching to nanoparticles to carry the virus and they are

> anticipating a clinical trail shortly.

>

> Mark

>