The History Of Albumin And Cancer Biology Essay

Introduction:

Truly revolutionary nanotechnology products, materials and applications, such as nanorobotics, are years in the future. What qualifies as "nanotechnology" today is basic research and development that is happening in laboratories all over the world. "Nanotechnology" products that are on the market today are mostly gradually improved products (using evolutionary nanotechnology) where some form of nanotechnology enabled material (such as carbon nanotubes, nanocomposite structures or nanoparticles of a particular substance) or nanotechnology process (e.g. nanopatterning or quantum dots for medical imaging) is used in the manufacturing process. In their on-going quest to improve existing products by creating smaller components and better performance materials, all at a lower cost, the number of companies that will manufacture "nanoproducts" (by this definition) will grow very fast and soon make up the majority of all companies across many industries. Evolutionary nanotechnology should therefore be viewed as a process that gradually will affect most companies and industries.

The variability and site recognition of biopolymers, such as DNA molecules, offer a wide range of opportunities for the self-organization of wire nanostructures into much more complex patterns. The DNA backbones may then, for example, be coated in metal. They also offer opportunities to link nano- and biotechnology in, for example, biocompatible sensors and small, simple motors. Such self-assembly of organic backbone nanostructures is often controlled by weak interactions, such as hydrogen bonds, hydrophobic, or van der Waals interactions (generally in aqueous environments) and hence requires quite different synthesis strategies to CNTs, for example. The combination of one-dimensional nanostructures consisting of biopolymers and inorganic compounds opens up a number of scientific and technological opportunities.

Nanomedicine:

Diagnostics

In the past few decades, imaging has become a critical tool in the diagnosis of disease. The advances in the form of magnetic resonance and computer tomography are remarkable, but nanotechnology promises sensitive and extremely accurate tools for in vitro and in vivo diagnostics far beyond the reach of today’s state-of-the-art equipment.

As with any advance in diagnostics, the ultimate goal is to enable physicians to identify a disease as early as possible. Nanotechnology is expected to make diagnosis possible at the cellular and even the sub-cellular level.

Quantum dots in particular have finally taken the step from pure demonstration experiments to real applications in imaging. In recent years, scientists have discovered that these nanocrystals can enable researchers to study cell processes at the level of a single molecule. This may significantly improve the diagnosis and treatment of cancers. Fluorescent semiconductor quantum dots are proving to be extremely beneficial for medical applications, such as high-resolution cellular imaging. While quantum dots could revolutionize medicine, unfortunately, most are toxic. However, recent studies conducted at the University of California, Berkeley, have shown that protective coatings for quantum dots may eliminate toxicity.

Therapy:

In terms of therapy, the most significant impact of nanomedicines is expected to be realized in drug delivery and regenerative medicine. Nanoparticles enable physicians to target drugs at the source of the disease, which increases efficiency and minimizes side effects. They also offer new possibilities for the controlled release of therapeutic substances. Nanoparticles are also used to stimulate the body’s innate repair mechanisms. A major focus of this research is artificial activation and control of adult stem cells.

Peptide amphiphiles that support cell growth to treat spinal cord injury; magnetic nanoparticles and enzyme-sensitive nanoparticle coatings that target brain tumours; smart nanoparticle probes for intracellular drug delivery and gene expression imaging, and quantum dots that detect and quantify human breast cancer biomarkers are just a few of the advances researchers have already made.

Interestingly enough, there could be massive shifts in economic value among pharmaceutical companies. While the new nanomedicines open up enormous market and profit potentials, entire classes of existing pharmaceuticals such as chemotherapy agents worth billions of dollars in annual revenue would be displaced.

Other areas that are increasingly attracting interest from nanotechnology researchers are tissue engineering, nanosurgery, and nanoparticle-enabled diagnostics and drug delivery.

Albumin nanoparticles:

Albumin is an attractive macromolecular carrier and widely used to prepare nanospheres and nanocapsules, due to its availability in pure form and its biodegradability,

nontoxicity and non-immunogenicity .Both Bovine Serum Albumin or BSA and Human Serum Albumin or HSA have been used. As a major plasma protein, albumin has a distinct edge over other materials for nanoparticle preparation. On the other hand, albumin nanoparticles are biodegradable, easy to prepare in defined sizes, and carry reactive groups (thiol, amino, and carboxylic groups) on their surfaces that can be used for ligand binding and/or other surface modifications and also albumin nanoparticles offer the advantage that ligands can easily be attached by covalent linkage. Drugs entrapped in albumin nanoparticles can be digested by proteases and drug loading can be quantified. A number of studies have shown that albumin accumulates in solid tumours making it a potential macromolecular carrier for the site-directed delivery of antitumor drugs.

Albumin and cancer:

Scheffel et al. and Gao et al. have reported the formation of albumin nanospheres by emulsification method. In this process the aqueous solution of the BSA was turned to an emulsion in room temperature and in plant oil. A mechanical homogenizer was used to homogenise the solution and the emulsion will be added to pre heated oil drop by drop. This will result in the evaporation of the existed water and this process will cause the formation of albumin nano particles. The disadvantage of the emulsification process is the need for applying organic solvents for the removal of the oily residues.

Lin et al reported the preparation of the HSA nanoparticles by desolvation method and a particle size of 100 nm was reported.

Muller et al[7]. reported the formation of the sub 200 nm range during the synthesis of BSA nanoparticles.

The effects of various cytostatic drugs were also reported. Maghsoudi et al. reported the study of 5- fluorouracil loaded BSA nanoparticles and optimization of various parameters for synthesis was studied. The in vivo release kinetics of the drug loaded nanoparticles was also studied and it maintained a constant drug release was maintained for 20 hours.

Sebek et al. reported noscapine loaded HSA nanoparticles with a particle size of about 150-200 nm with a drug loading efficiency of about 85-96%.

Ganciclovir loaded albumin nanoparticles were reported by Irache et al. They reported that when the drug was incubated with the protein prior to the formation of nanoparticles resulted in the sustained release of the ganciclovir.

Doxorubicin loaded cationic albumin nanoaparticles were studied for the effective treatment of the breast cancer by Abbasi et al. They found that the cytotoxicity of these nanoparticles was highly reduced.

Polymer coated albumin nanoparticles were reported by Wang et al. BMP-2 loaded albumin nanoparticles were synthesised and found that no toxicity was induced due to the polymer coating. ALP induction, calcification and the bioactivity of the BMP-2 was fully retained in the polymer coated nanoparticles.

Yang et al. reported the synthesis and characterisation of the 10-HCPT loaded albumin nanoparticles to increase the stability and to improve the anticancer activity. The release of HCPT was found to be more than 90% in 20 hours in the trypsin medium. The particle size was reported was about 600 nm.

Synthesis and characterisation of the pacilitaxel loaded albumin nanoparticles were reported by Zhao et al. The drug loaded nanoparticles were spherical in nature with an average particle size of 200 nm and the drug loading efficiency was found to be 95.3%.

Das et al. reported the study of aspirin loaded nanoparticles and its implications in the drug release in the treatment of arthritis. The particle size obtained was about 200 nm and sustained release of drug was ensured.