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| Home > Articles > Biotechnology The Next Big Wave |
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Biotechnology The Next Big Wave |
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The first human protocol for gene therapy was performed in Adenosine deaminase (ADA) deficient patients in 1990 at the national institute of health. For Severe combined immuno deficiency disease (SCID) and other diseases, gene therapy is life saving.
Antisense Therapy
Nucleotide blockade and antisense technology focuses upon the study offunction of specific proteins and intracellular expression. The sequence of a nucleotide chain that contains the information for protein synthesis is called the sense sequence. The nucleotide chain that is complementary to the sense sequence is called the antisense sequence. Antisense drugs recognize and bind to the nucleotide sense sequence of specific RNA molecules, preventinq the synthesis of unwanted proteins.
Antisense Therapy
"It is considered to be a genetic kind of magic bullet for the treatment of cancers and other diseases". Antisense technology is part of a new approach termed reverse genetics.
Peptide technology
Peptide technology involves the screening for polypeptide molecules that can mimic larger proteins. This is intended to afford more simple products that can be more stable and easier to produce. These peptides can serve either as protein receptor agonists (or) antagonists.
Products of Biotechnology
Biotechnological drugs can be classified into major classes such as antisense drugs, clotting factors hematopoietic factors,tissue growth factors and vaccines. Biotechnological drugs are distinguished based on whether they are physiologic or non-physiologic peptides or whether they are new biotechnology products.
Anticoagulant drug
Lepirudin - Refludan: Lepirudin (r DNA), a recombinant hirudin derived from yeast cells, is a highly specific direct inhibitor of thrombin. It is the first of the hirudin class of anticoagulants. The polypeptide is composed of 65 amino acids and has a molecular weight of 6479.5 daltons. Natural hirudin is produced in trace quantity as a family of highly homologous isopolypeptides by the leach hirudo medicinalis.Biosynthetic lepirudin is identical to natural hirudin except for substitution of a leucine molecule for isoleucine at N-terminal end of the molecule and the absence of a sulphate group on the tyrosine molecule at position 63.
Antisense Drugs
Formivirsen Sodium - Vitravene: Formivirsen sodium injectable is an antisense drug that has been approved for the local treatment of cytomegalovirus (CMV) in patients with AIDS who are intolerant of or have a contraindication to other treatments for CMV retinitis. Also, it may be used in thoseinstances where previous treatmentforCMVretinitis failed. Formivirsen sodium, a phosphorothioate oligonucleotide, is administered by direct injection into the vitreous body of the eye.This oligonucleotide is targeted specifically to the CMV genetic information so that it can shut down the CMV virus, but do not. interfere with the functioning of human DNA.
Efavirenz - Sustiva:
Efavirenz is a non-nucleoside reverse transcriptase inhibitor and the first anti-HIV drug to be approved by the FDA for once daily dosing in combination with other anti HIV drugs. Clinical trials demonstrated that efavirenz reduces plasma viral RNA to below quantifiable levels in a majority of HIV-1 infected naive and treatment experienced individuals.
Clotting Factors :
Hemophiliacs, suffer from internal bleeding because of a lack of clotting protein factors. Historically, their treatment has been infusions of protein derived from humanblood. Now, through genetic engineering, factors can be createdwithout using donor blood that produce more nearly contaminant-free products and therefore expose the patient to fewer contaminants.
Systemic Antihemophilic Factors - Kogenate, Recombinate
Human recombinant AHF (rAHF) is a sterile, nonpyrogenicconcentrate with biologic and pharmacokinetic activitycomparable to that of plasma-derived AHF. New products are made by modifying hamster cells through biotechnology processes so that they produce a highly purified version of AHF factorVIll.
Colony Stimulating Factors: (CSFs)
Recombinant human CSFs have potential for wide use in theareas of oncology, inherited disorders (eg. congenita neutropenia) and infectious disease (eg. AIDS). Patients with low amounts of endogenous CSF and are prone to secondary infections because of diminished resistance associated with some forms of cancer, more commonly, suppressed marrow function after the use ofmyelotoxic chemotherapy.
Granulocyte Colony Stimulating Factor (G-CSF)
Filgrastim: Produced by recombinant DNA technology, this drug stimulates the production of neutrophils within the bone marrow. It is approved for chemotherapy related neutropenia and is indicated (to decrease the incidence of infection, as manifested byfebrile neutropenia) in patients with nonmyeloid malignancies who are receiving myelosuppressive anti-cancer drugs and exhibiting severe neutropenia with fever. This drug also can be used as an adjunct to myelosuppressive cancer chemotherapy to help speed the recovery of neutrophils after treatment and to reduce serious infection risk.
Erythropoietins
Erythropoietin is a sialic acid-containing glycoprotein that enhances erythropoiesis by stimulating the formation of proerythroblasts and the release of reticulocytes from bone marrow. It is secreted by the kidney in response to hypoxemia and transported to the bone marrow through the plasma. Kidney disease also impairs the bodys ability to produce this substance, and thus results in anemia. An exciting alternative is the genetically engineered epoetin alpha, to stimulate erythropoesis. Hence, erythropoietin therapy may be beneficial in cancer patients. Becaplermin-Regrenere Becaplermin is a recombinant human platelet derived growth factor (rh PDGF-BB) for topical adjuctive treatment of diabetic ulcers, a form of pressure ulcer, of the lower extremities that extend into subcutaneous tissue or beyond and having a sufficient blood supply. It is reasonable to assume that it might find utility as an adjunct to good pressure ulcer care.
Aldesleukin-Proleukin
Aldesleukin is synthetically produced by a recombinant DNA process involving genetically engineered Escherichia coli containing an analog of the human interleukin-2 gene. An expression clone that encodes a modified human interleukin-2 results from genetic engineering techniques used to modify the human interleukin-2 gene. Aldesleukin differs from naturally occurring interleukin-2 in that it is not glycosylated because it is derived from E.Coli, the molecule has no N-terminal alanine and the molecule has serine substituted for cysteine at Amino acid position 125.
Tissue PlasminogenActivators
These are substances produced in small quantities by the inner lining of blood vessels and by the muscular wall of the uterus.Tissue plasminogen activators prevent abnormal blood clotting byconverting plasminogen, a component of blood, to the enzymeplasmin. This latter substance breaks down fibrin, the main constituent of a blood clot. Genetic engineering has prepared these substances artificially and they are used as thrombolytic agents. They are used in conditions of heart attack, angina and occluded arteries. Vaccines Genetically engineered vaccines use a synthetic copy of the protein coat of a virus to "fool" the bodys immune system into mounting a protective response. This avoids the use of live viruses and minimizes the risk of causing the disease the vaccines were intended to prevent. The first genetically engineered vaccine for use in the United States was approved by the FDA in 1986 for Hepatitis B, a wide spread liver infection. This vaccine has now replaced the plasma -derived vaccine.
The future of Biotechnology products
The future will see the development of more protein-based pharmaceuticals as a result of modern bio-technologic strategies, including the development of artificial genes. These
protein-based drugs will present unique challenges because of intrinsic instability, multifaceted metabolic properties and limited lastrointestinal absorotion.
Biotechnology - The Next Big Wave
International hub for contract research and manufacturing. A number of start-ups have entered the industry over the past four to five years, inspired by the success of Indias leading btechnology company Biocon. But sadly, just five companies (Serum institute, Pune; Biocon, Bangalore; Panacea Biotech, Delhi; Nicholas Piramal, Mumbai and Move) Nordisk, Bangalore) accountforover40percentof the total Indian marketshare,
Driving factors that would help India reach this mark
Education : Over the last decade or two, India has developed adequate infrastructure and trained manpower in modem as well as classical biotechnology, mainly due to active support of the Dartment of Biotechnology.
Government initiatives: Budgetary allocations to the biotechnology sector have more than trebled from $150 million in 1987-88 to $500 million in the fiscal year 2002-2003. Further, the union budget has been offering fiscal incentives to promote private sector efforts in biotech R&D, the most noteworthy being the provision of a 150 percent tax-deducation for R&D spending on biotechnology in FY 2002.
Specific concerns : There are several factors that can act as an impediment to the expected growth in this sector. M. Divesh (MD, Emellen Biotech) says that the following are the roadblocks that fack this sector:
Inadequate funding for SMEs (Small & Medium Enterprises) : Although the government of India has allocatedfunds to this sector, it should develop some mechanism to ensure that adequate funding reaches SMEs and is not all lapped up by large companies.
Unaccommodating policy environment : An important impediment that enterprises in this sector face is the inadequate and bureaucratic policy environment. The National Biotech Policy should improve the situation but what remains to be seen is exactly how the policy is implemented and whether it sets definite time frames for various approvals.
The Future--
In a nutshell, with serious R&D work, adequate funding and an opportune breakthrough, any of the present biotech companies could become the In fosys of the future. A distinct advantage of these biotechnologically derived proteins over proteins from natural sources is enhanced purity. Hepatitis B virus and the human immunodeficiency virus (HIV) are capable of contaminating proteins and enzymes from human plasma. Products derived from recombinant technology will not have coextracted contaminants.
Advantage
- Enhanced purity
· Products derived from recombinant technology will not have coextracted contaminants.
· Monoclonel antibodies have been used in home tests for confirmation of pregnancy (or) predicting ovulation.
· Development of artificial genes have been made possible.
· The therapy with biotechnologica products will eventually supplement chemotherapy for many malignancies.
· Biotechnology allows significant reduction of risks of contamination through infectious pathogen.
Disadvantages
- Time consuming
· Expensive
· Skilled labourare required Results achieved are not upto the mark
Future of Biotechnology
The future will also see the creation of more products for "inhome" testing. Monoclonal antibody-based diagnostic tests that are now restricted to physician use are under development for home testing. These include products for infectious disease processes (eg., AIDS, chlamydia trachomatis, streptococcal throat infections). In addition, it is anticipated that monoclonal antibody-based tests will also be available to assay blood /plasma concentrations of a number of drugs (e.g., digoxin,phenytoin, theophylline).To date, monoclonal antibodies have been used in home tests for confirmation of pregnancy (or) predicting ovulation. The self-test kit will enable a woman to monitor urine levels of pregnanediol to determine when fertilization is possible. A woman could then avoid intercourse during her fertile period and prevent the occurrence of pregnancy.
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| Posted : 10/26/2005 |
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