Spelling suggestions: "subject:"polynucleotide"" "subject:"oligodeoxynucleotides""
1 |
Chemical modification of nucleic acids under biological conditions [Part I] Part II. The large scale purification of yeast tRNA and procedures and problems in the amino acid acceptor assay /Kirkegaard, Leslie Harvey, January 1969 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
|
2 |
Synthesis And Characterization of Cationic Lipids And Carbon Nanomaterials Based Composites for the Delivery Of Bioactive Oligo/Polynucleotides and Drugs In Vitro and In VivoMisra, Santosh Kumar January 2013 (has links) (PDF)
The biggest hurdle in success of gene and drug therapy is designing and preparation of suitable bio-nanomaterials to carry the desired nucleic acid and drug to the targeted site. The work described in the present thesis encompasses two different approaches for the delivery of bioactive oligo/polynucleotides and drugs in vitro and in vivo using either cationic lipids or their nanocomposites with different carbon nanomaterials. The idea of using carriers for oligo/polynucleotides and drugs came into existence because of numerous physiological barriers in pathway of delivery of naked oligo/polynucleotides or drugs which reduces the overall activity of these bioactives in biological systems. These barriers trigger scientific research toward the preparation of appropriate biomaterials which can overcome the physiological barriers and improve the activity of bioactive oligo/polynucleotides and drugs in cellular systems. Toward this end, the design and synthesis of different cationic lipids and carbon nanomaterials were undertaken as described in seven chapters of the thesis.
A series of novel cationic lipids with structural variability was prepared and used for gene delivery in vitro. They were further tuned chemically to sustain delivery efficiency in high serum percentage during in vitro transfection. These serum compatible lipids were used to perform transfection of reporter gene plasmid and found to be more efficient compared to the some well known commercial products for the same purpose.
Another series of novel lipids were synthesized for the targeted gene delivery in vitro. These tryptophan based cholesteryl lipids were used to prepare mixed liposomes. These mixed liposomes were highly efficient in targeting sigma receptor rich HEK293T over sigma receptor negative HeLa cells. Mixed liposomes were also prepared for selective targeting of αvβ3 and αvβ5 integrins in gene transfection protocol using a palmitoyl-RAFT-RGD4 template.
A mixed liposomal formulation was developed to carry out anti-sense siRNA mediated knockdown of Smad-2 protein with better efficiency compared to some of the best known commercial products for the same purpose. These mixed liposomes were also highly efficient for regression via induction of p53 mediated apoptosis in xenograft tumors developed in nude mice.
Carbon nanomaterials have been extensively explored as nanoscale gene/drug carriers for potential applications. But the challenge is to solubilize these highly hydrophobic materials in aqueous medium for use in biological systems. Although there are reports for covalent modifications of such nanomaterials but it could be done only with the loss of some beneficial features of these materials. Herein a non-covalent technique has been efficiently used to suspend single walled carbon nanotubes in water using biocompatible cationic lipids. These nanosuspensions were used to complex plasmid DNA and transfect them in vitro. They proved to be highly serum compatible DNA carriers which did not drop the efficiency even in very high percentage of serum. Similarly exfoliated graphene was modified with cationic lipid and serum components to improve IC50 of Tamoxifen citrate and Methotrexate to a considerable extent in vitro. The improved Methotrexate formulations were highly efficient for regression in size of xenograft tumors developed in nude mice.
Thus, the present thesis entails generation of cationic lipids and carbon nanomaterials based nanocomposites which were not only highly biocompatible themselves but their efficiency was found many fold better compare to some of the best commercial delivery agents. These were useful for the delivery of various bioactive oligo/polynucleotides and drugs in vitro and in vivo.
|
3 |
Exploration of bioactive additives for hyaluronan based hydrogels : A literature study / Undersökning av bioaktiva tillsatser till hyaluronan-baserade hydrogelerEriksson, Tilda, Quakkelaar, Lisa, Parkstam, Alexander, Karlsson, Alina, Askari, Mansourah, Said Ahmed, Shukri January 2022 (has links)
Hyaluronan (HA) is a substance that is commonly used in biomedical applications in the form of hydrogels. One of these biomedical applications is dermatological fillers where HA is cross-linked with 1,4-Butanediol diglycidyl ether (BDDE) to reduce its rapid turnover within tissue. The filler gives a volumetric effect that can fill out wrinkles. This literature study was conducted in collaboration with Galderma to determine if there is research that explores additives to HA hydrogels that give both volumetric and biological effects when applied as filler. Biological effects that improve the skin's appearance and complexion such as a rejuvenation of the skin was preferable. Both polynucleotides and mannitol show great potential to act as additives in injectable hyaluronan hydrogels. The main effect of polynucleotides (PN) added in hydrogels is that it is collagen stimulating and provides a more natural tissue regeneration. Rheological properties of the filler change with the addition of PN, where elasticity, viscosity and viscoelasticity have been shown to increase. PNs show no toxicity and are considered safe to inject. The study of mannitol has shown that it does not give a volumetric effect after the injected hydrogel has been broken down. What mannitol can help with, is to prolong the life of the hydrogel and reduce the swelling that is a common side effect after an injection. In addition to this, mannitol is a safe substance to inject.
|
Page generated in 0.0666 seconds