Preparation And Research Of Fluorescent Gene Carriers

Cancer is one of the major diseases which seriously threaten humanhealth, and the incidence of cancer also showed an increasing trend yearby year. In addition to surgical excision, the conventional treatmentsfor cancer mainly include chemotherapy and radiotherapy, but this twomethods will not only kill cancer cells but also kill normal cells, causingdamages to normal tissues, organs. Chemotherapy and radiation therapyalways bring great pains to patients. Gene therapy is believed to overcomethe drawbacks of the above treatments, and cure cancer radically. Genetherapy is widely studied recently, and is engaging a very fastdevelopment. Gene therapy is carried out by transferring therapeutic genegenes into the body using gene carriers, the treatment is achieved by theexpression of the targeted genes. Gene carrier is the key factor in genetherapy. The desirable gene carrier should possess high transfectionefficiency, low toxicity and low immunogenicity. Gene carriers can beclassified into viral gene carrier and non-viral gene carrier. The viralgene carrier is now more widely used, but it has many limitations,restrictions on the development and application. Non-viral gene vectorscould be prepared in easy process and in large scale. And they also havesafe performance because of lacking immunogenicity. At the same time thetransfection efficiency for non-viral carriers is relative low comparedwith viral gene carriers, targeting delivering properties for non-viralgene carriers is also needed to be improved.PEI (polyethylenimine) is one of the most studied non-viral genecarriers. But PEI itself has many shortcomings, such as lower transfectionefficiency, higher cytotoxicity and non-biodegradability, also does not have the function such as tracing function. These disadvantages hinderits further development and application.Gold nanoparticles are catching more and more attentions in recentyears due to their good fluorescent properties and biologicalcompatibility. It is desirable to combine PEI and gold nanoparticlestogether to get a gene carrier with high transfection efficiency, lowcytotoxicity and fluorescent properties. This paper first studied themodification of PEI with different molecular weight. PEI and metalnanoparticles were linked together by the sulfur metal bond. This papermakd a comparative study to select a gene carrier with strong fluorescentproperties, higher transfection efficiency. This gene carrier wasprepared by one-step process. Studies on the gene carrier’s zeta potential,particle size, fluorescent stability and biological imaging were carriedout.