Design and Development of New Class of Polymeric Prodrugs using Ring Closing Metathesis Polymerization / Cyclopolymerization

Kumar, Pawan (2021) Design and Development of New Class of Polymeric Prodrugs using Ring Closing Metathesis Polymerization / Cyclopolymerization. PhD thesis, Indian Institute of Science Education and Research Kolkata.

Text (PhD thesis of Pawan Kumar (15RS057)) 15RS057.pdf - Submitted Version Restricted to Repository staff only Download (4MB)

Abstract

Cancer is a disease with foremost death rate globally after cardiovascular disease. The treatment of cancer has progressed substantially in recent years. Surgery, chemotherapy, immunotherapy and radiotherapy are the majorly used treatment of cancer. Among these chemotherapeutic treatment shows great potential in treatment of cancer. There are number of chemotherapeutic drugs are available commercially. Issue related to these chemotherapeutic drugs are low solubility in water, toxic to normal cells, low efficacy, etc. Polymeric prodrugs based nanocarriers are well-known for its biocompatibility, biodegradability and ability to target. Polymers help in optimization of chemical and physical properties as per our requirement. Polyethylene glycol is well-known for its solubility in water. It also helps in reducing the interaction to surface of particles leads to preventing protein adsorption. These nanocarriers help to accumulate at the tumour site by the enhanced permeation and retention (EPR) effect because of its leaky vascular nature. Our research is mainly focused on five aspects, i.e. (1) delivery of chlorambucil, (2) polymer modification, (3) targeted delivery, (4) cyclopolymerization technique and (5) biosensors by carbohydrate – protein interaction. Chlorambucil is one of the effective chemotherapeutic drugs, but it limits in treatment due its non-fluorescent nature. Post-polymerization modification with multiple steps leads to low yield. Here, we have tried to increase the yield after multiple steps of post-polymerization modification. Targeted delivery is one of the effective treatments in cancer. Targeted delivery helps to increase drug efficacy at the tumour site and reduce toxicity to other normal cells. It happens in two ways, i.e., organelles target inside the cells or receptor targeting on the surface of the cells. Cyclopolymerization is one of the polymerization techniques which is known for last few decades. Till now, synthesis based on cyclopolymerization is explored a lot with different catalyst and different 1,6-heptadiynes based monomer. We have explored first time this polymer in field of drug delivery application. Details of my work shall be found in further chapters. In chapter 2, polymer PMPDC was synthesized by cyclopolymerization, a living polymerization technique, of 1,6-heptadiynes based functionalized moiety with mPEG and chlorambucil. Living polymerization help in synthesizing controlled molecular weight, narrow PDI, morphology, size, etc. After polymerization, backbone of polymer leads to form continuous conjugated backbone with active in UV region. To track the drug release in different pH and cell internalization, by control polymerization technique molecule polymer PMPDP was synthesized using 1-pyrenebutyric acid instead of chlorambucil. All analytical study for confirmation of formation of all synthesis were carried out. To study the size and shape of polymers, self-assembly study was performed by DLS and TEM. MTT and cellular uptake study were performed with HeLa cell line. In chapter 3, we developed a system which can be used as combinational drug delivery. So, in this chapter, we tried to synthesize 1-pyrenebutyric acid and chlorambucil in one monomer. It was also expected that, it will help in real-time monitoring of biodistribution of polymer in cells. Towards this, monomer MPPDC was synthesized using 1,6-heptadiynes functionalized moiety with mPEG, 1-pyrenebutyric acid and chlorambucil. It was then polymerized by cyclopolymerization technique to get polymer PMPPDC. Further all the characterization study was carried out to confirm the formation of polymer PMPPDC followed by self-assembly and cytotoxicity study. In chapter 4, fluorophores are known as the absorbing and emitting light which helps in tracking of non-fluorescent drugs in biological systems. Fluorophores are attached to non-fluorescent drugs either by covalently or non-covalently. Covalently attached drugs to fluorophores helps in real-time monitoring of drug release and biodistribution in the medical treatment. Chlorambucil is attached to coumarin derivatives. It is then attached to MPSD, a mPEG functionalized 1,6-heptadiyne moiety to form monomer MPDCC followed by polymerization to get polymer PMPDCC. All characteristic study with self-assembly and cellular study are performed. In chapter 5, triphenylphosphine (TPP) based moiety was widely used as effective targeting molecule for mitochondria organelle for last thirty years. In this chapter, first TPP was functionalized with mPEG moiety in four steps to get PEGTPP. On the other hand, chlorambucil was attached to coumarin based fluorophores, HYCOUCHO for real-time monitoring of delivery and biodistribution in the cells. Then these two moieties were attached to DIOL to get monomer MPTPDCC. It was further polymerized to get PMPTPDCC by cyclopolymerization followed by self-assembly, zeta potential and MTT study. In chapter 6, cell surfaces consist of glycoproteins and glycolipids where oligosaccharides attached to protein or lipid backbone play pivotal roles towards cellular recognitions. Glycopolymers have potential for mimicking the cell surfaces of glycoproteins, so in this chapter, first Mannose-N3 was taken from Prof. Balaram Mukhopadhyay sir’s lab. On the other hand, alkyne functionalized moiety RCM-PROP was synthesized after post polymerization modification of MONOACID. Using click reaction of Mannose-N3 and RCM-PROP, we synthesized our targeted molecule RCM-MAN and characterized all the steps. Then its self-assembly and interaction with concovalin A were carried out. Cytotoxicity of RCM-MAN was also carried out in MCF 7 cells to check its viability.

Actions (login required)

View Item