Poster Presenter

Collagen Coated Liposome Nanospheres As A Targeted And Controlled Delivery System Of Zudovudine (AZT) and Doxorubicin (DXR)
P.K. Sehgal, S. Sadulla and Krishnamoorthy Ganesan
India

Collagen coated liposome nanospheres (CCLNS) have been assessed for use as a targeted and controlled delivery system of Zudovudine (AZT) and Doxorubicin (DXR) for treatment of HIV and cancer respectively.

The particle size, shape and zeta potential, surface morphology, drug encapsulation and release profile of AZT and DXR on CCLNS were determined by using particle size analyzer, FT-IR spectra, Scanning electron microscopy (SEM), Atomic force microscopy (AFM) and the in vitro drug release profile was determined using UV-Visible spectra and HPLC.

Collagens have various applications as biomaterials and are widely used in tissue engineering and, as carriers for delivery of drugs such as antibiotics, vaccines, proteins and genes etc. Liposomes also are of great scientific and medical interest due to their ability to protect and to carry hydrophilic and/or hydrophobic molecules and for their natural affinity toward lymphatic system and delivery of various low and high molecular weight drugs, proteins, and genes, and the targeting them to cellular and sub-cellular targets. Nanocarriers like liposome - undoubtedly represent the most extensively studied and advanced Drug delivery system (DDS), it can facilitate lymphatic targeting and prolong the residence time at the target site. These nanoscale liposome vesicles, and their micron-sized counterparts, offer potential means of delivery of drug in the treatment of cancerous and infectious diseases. DXR is a potent antineoplastic agent, active against a wide range of human cancer including lymphomas, leukemia and solid tumors. However, administration of this drug produces acute toxicity in the form of bone marrow depression, alopecia and oral ulceration. DXR entrapped in liposomes shows reduced non-specific toxicity and maintains or enhances anticancer effect. The liposomal formulation of AZT abrogated the hematopoietic toxicity of AZT resulting in normal red blood cells and circulating neutrophil and monocyte levels. Liposomal formulation was developed to treat Kaposi's sarcoma, an AIDS-related cancer that causes lesions to grow under the skin, in the lining of the mouth, nose and throat, or in other organs. In these above combination systems, collagen is supposed to make CCLNS more stable and less permeable, thus providing a targeted and controlled/sustained delivery system. The lecithins-collagen complex was proposed to be maintained by electrostatic interaction between the zwitterionic polar heads of phosphatidylcholine, phosphatidylserine and phosphatidyinositol, the phospholipids used for such a study, and the amino acid side chains of the collagen. The results suggested that CCLNS containing AZT and DXR for DDS could be useful for treatment of HIV and cancer for penetration of blood-brain barriers, blood-placental barriers and lymphatic and nervous systems. To overcome these limitations, encapsulation of drug in CCNLS may offer the following potential advantages: 1) reducing or prohibiting drug affinity to non-target components and decreasing undesired interactions, 2) acting as a long-term preservative in drug systems, 3) protecting drug from inhibitors or unfavorable conditions, 4) decreasing the risk of emergence of resistant strains and 5) providing a means for targeting the microorganisms, and 6] decreasing permeability and increasing drug releasing to target site.

These DDS are very effective offering several advantages including an increase in drug bioavailability and retention at the target site and improving the adherence or adhesion to the designated target and sustaining drug release depots. Hence the present study could help the effective management of AIDS and cancer treatment via selective lymphatic targeting, blood-brain barriers and blood placental barriers of drugs to control HIV and cancerous cells. However, studies on animal model needs to be carried out before using these devices on HIV and cancer patients.