M.Phil / MS
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This collection archives the complete set of theses produced by students of the COMSATS University Islamabad, Lahore Campus.
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Item Computational Investigation of Functionalized Carbon Dots for Detection of Enrofloxacin(Library Information Services, COMSATS University Islamabad, Lahore Campus, 2025) Fatima Mahmood; CIIT/SP24-R06-019/LHR; Dr. Sobia Tabassum; LHR TP 10024The overuse of antibiotics is a leading cause of drug-resistant bacteria. Diagnosis and prevention from Enrofloxacin (ENR), a veterinary drug, are required. Due to its overdose it cause serious issues in humans. Many existing methods for detecting antibiotic residues in food are expensive and not easily accessible. There is a need to develop efficient and affordable alternatives. This study explores the functionalization and doping of Carbon dots to enhance its adsorption on ENR. Adsorption energy is depending upon the optimized geometries, adsorption energies, NBO, FMO, QTAIM and IRI analyses. Results reveal the physiosorption of ENR on M@NCDs. ENR was adsorbed on M@NCDs with the adsorption energy of -12kcal/mol. IRI and QTAIM confirmed Van der Waals interactions between ENR and M@NCDs. The band gap changes is determined by molecular orbital analysis, to study the electronic transitions. NBO and MEP analysis confirms the charge transfer from ENR to M@NCDs. The charge transfer decrease the bond stretching frequency of carbonyl bond of ENR in three complexes (ENR-Li@NCDs, ENR- Na@NCDs and ENR-K@NCDs). The IRI analysis supports the potential application of M@NCDs in IR-based sensors.Item Biological Active Hydrogels with Efficient Drug Delivery Potential by B-O/-N Co-ordination for the Treatment of Periodontitis(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Talia Ghaffar; SP22-R06-008; Dr. Sobia Tabassum; LHR TP 8647Periodontitis, an infection-induced inflammatory state affecting the gums, poses a substantial peril to periodontal tissues, potentially culminating in tooth loss and broader ramifications for health. Addressing this formidable challenge necessitates the development of a proficient system adept at combating bacteria and fostering tissue regeneration. In the present investigation, biologically potent self-repairing hydrogels were engineered, incorporating anti-inflammatory agents and antimicrobial polymeric carbon dots (PCDs). The PCDs exhibited the capacity for intracellular penetration, and those functionalized with the antibiotic Metronidazole demonstrated efficacy against E. coli and S. aureus, rendering them potent antibacterial agents capable of eradicating bacteria residing within cells. The hydrogel synthesis encompassed biologically active polymers such as gelatine and polyvinyl alcohol, the antioxidant and anti-inflammatory gallic acid, and regenerative ceramics hydroxyapatite. The ratio of crosslinkers glutaraldehyde and borax was fine-tuned to instill the requisite self-repairing attributes into the hydrogels. Rheological analysis of the prepared hydrogels revealed enhanced mechanical properties with the incorporation of PCDs, evidenced by an increase in the critical strain ratio from 41% to 180%, self-healing reaching 88%, and a reduction in viscosity to 11 Pas. The hydrogels exhibited a swelling ratio of 130%, with sustained drug release, 49% of Gallic acid, and 61% of MCDs in 17 days, indicating prolonged therapeutic effects, while water contact angle measurements affirmed the essential hydrophilicity facilitating cellular attachment. Degradation studies substantiated the biodegradable nature of the hydrogels. In summary, thorough characterizations affirm the safe and efficacious utilization of hydrogels in the treatment of periodontitis, devoid of adverse effects.Item Self-healing Hydrogels as an Efficient Local Drug Delivery System to Treat Periodontitis(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-26) Shaista Shaukat; FA21-R06-013; Dr. Sobia Tabassum; LHR TP 8445Periodontitis is an infection-related, inflammatory condition of the gums. The periodontal tissue is harmed. It can result in tooth loss and a host of other health issues if left untreated. A system that is effective against bacteria and has the ability to regenerate tissue is needed for treatment. Hydrogels that are both affordable and antimicrobial have been created in this study as an efficient local drug delivery system. The synthesis of hydrogels includes polymers polyvinyl alcohol, gelatin, hydroxyapatite, glutaraldehyde and borax as a crosslinkers. The hydrogel is self-healing and has mechanical strength. Metronidazole loaded on it which very effective antibiotic against gram negative strains of bacteria that cause periodontitis. Hydroxyapatite modified with arginine which enhance the wound healing capability of hydrogels. Different characterizations have done for hydrogels FTIR shows dual crosslinking in hydrogels. Drug release study shows the significant release of drug which is helpful in first 24h of healing. Water contact angle measurement shows that the hydrogels are hydrophilic which is helpful in the attachment with cells. Degradation studies confirm the biodegradability of hydrogel. The hydrogels are effective against both E. coli and S. Aureus strains of bacteria. All the characterizations and studies lead to healthy use of hydrogels without any side effect in the treatment of hydrogels.Item Antibacterial dual cross-linked hydrogels for Periodontal Regeneration(Library Information Services COMSATS University Islamabad Lahore Campus, 2022-02-26) Fakhira Bashir; FA20-R06-004; Dr. Sobia Tabassum; LHR TP 7878Periodontitis is one of the most common gum diseases caused by bacterial infection. It affects teeth's surrounding bone and tissues. It is important to treat the disease promptly as it not only results in tooth loss but also affects the general health of the patient. It is extremely common in young individuals with occurrence rates of approximately 50% across the world. Different graft materials are used to treat periodontal defects, but unpredictable clinical outcomes of existing solutions encourage developing novel materials with enhanced functionality. This study aimed to formulate oval proteins, hydroxyapatite (HA) and PVA based anti-bacterial dual cross-linked hydrogels for periodontal regeneration. Potential non-toxic and biodegradable oxidized alginate, borax and divalent ionic (Cu+2, Zn+2, Ca+2) solutions were used as cross linking agents. Oval proteins act as efficient gelling agent and can mimic the ECM microenvironment. Hydrophilicity, potential bio-degradation, outstanding cytocompatibility, less cytotoxicity, surface alignment features, and self-healing are some of distinctive properties of prepared hydrogels. Hydroxyapatite (HA) is a bio-ceramic and used as bone regeneration material.Item Designing Donor-Acceptor Small Molecules For Organic Solar Cells With Promising Photovoltaic Parameters(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-23) Shahzaib Ijaz; SP19-R06-001; Dr. Sobia Tabassum; LHR TP 7340Cyclopentadithiophene (CPT) is one of the most efficient electron donating unit and has been reliably used in highly efficient optoelectronic applications because of its unique characteristics of excitation of electrons by fused thiophene ring derivatives, the rigidity and the high flatness of its structure. In order to meet the increasing demand of high-efficiency photovoltaic compounds in modern high-performance applications, we have designed and explored new CPT-based donor-acceptor-donor-acceptor-donor based materials with higher efficiency from d-CDT(PTTh2). Three novel isostructural D1-A-D2-A-D1 based low band gap small molecule donors (SMDs) having one-atom replacement (Flourine, Chlorine and Hydrogen) in acceptor unit of benzothiadiazole (BTZ) were designed and investigated by density functional theory (DFT) simulations. The designed molecules are 7,7'(7H-cyclopenta[1,2-b:3,4-b']dithiophene-2,5-diyl)bis(6fluoro4(5'hexyl[2,2’[2,2' bithiophen]-5yl)benzo[c][1,2,5]thiadiazole) (CPT1), its chlorine analogue 7,7'-(7H-cyclopenta[1,2-b:3,4-b']dithiophene-2,5-diyl)bis(6-chloro4-(5'-hexyl-[2,2'-bithiophen]-5yl)benzo[c][1,2,5]thiadiazole) (CPT2) and their hydrogen analogue 7,7'-(7H cyclopenta[1,2-b:3,4-b']dithiophene-2,5diyl)bis(4-(5'-hexyl-[2,2'bithiophen]-5 yl)benzo[c][1,2,5]thiadiazole) (CPT3). All are based on the strong electron rich unit CPT and electron withdrawing BTZ acceptors. The structures of designed compounds were optimized at DFT/B3LYP/6- 311 g(d,p). The new designed donors CPT1, CPT2, CPT3 showed superior absorption range found at the wavelengths of 715nm,674nm and 705nm respectively as compared to 667nm of reference molecule d-CDT(PTTh2) in chloroform solution. DFT calculations revealed that CPT1,CPT2 and CPT3 transfer their charges efficiently with band gaps 2.0 eV,2.21 eV and 2.1 eV respectively. The calculated open circuit voltages range from 0.55 eV to 0.70 eV, while CPT2 have a significantly higher open circuit voltage than the open circuit voltage of 0.62 of reference molecule d-CDT(PTTh2). Charge transfer mobilities of designed molecules are also superior than d-CDT(PTTh2) because of their lower reorganization energies ranging from 0.00114 to 0.038282 for electron and 0.11101 to 0.44505 for hole. This DFT investigation revealed that tuning of organic compounds can further enhance the efficiency of SMDs in bulk hetero-junction (BHJ) organic solar cells (OSC’s). DFT calculations showed that one atom substitution has a slight but notable effect on band gaps of frontier molecular orbital (FMOs) which affects the absorption ranges, reorganization energies, Voc, FF and PCE of SMDs in BHJ OSC. Our investigations suggest that the designed molecules can work as fine SMDs when coupled with PC71BM as an acceptor in BHJ OSC.Item Antibacterial Functionally Graded Composite Membrane for Periodontal Regeneration(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-23) Azka Shahid; FA19-R06-026; Dr. Sobia Tabassum; LHR TP 7318Periodontitis is a gum disease caused by bacterial infections. It damages the soft and hard tissues that clasped teeth position and leads to teeth loss. Periodontal disorder affects 90% of people throughout the world. A functionally graded membrane having mechanical strength, porosity, and good regeneration capability of hard and soft tissue of periodontal offers effective recovery In this study, an antibacterial, functionally, and structurally graded bilayer membrane was synthesized by using a greener crosslinker 2,3- dialdehyde cellulose (DAC). Chitosan (CH), Oval albumin (OA), and crosslinker DAC were used to fabricate the membrane for the soft tissue regeneration. The CH, OA Hydroxyapatite (HA), and Copper substituted hydroxyapatite (Cu-HA) were used to prepare membrane for the growth of hard tissue. To install antibacterial properties and improve biological activity in the proposed membrane HA was substituted with copper. The biopolymer used in this study possesses good regeneration ability. CS is the second most abundant natural biopolymer well known for its biocompatibility, bioactivity. Oval albumin reported to activate cellular adhesion and regenerations. Crosslinker dialdehyde cellulose offers good biocompatibility compared to commonly used toxic poly aldehyde-based crosslinkers. HA is a gold standard biomineral having an excellent ability to regenerate hard tissue. Oxidation of cellulose to dialdehyde cellulose was done by using NaIO4. Four different membrane samples with different amounts of crosslinkers were prepared to evaluate the effect of crosslinkers on membrane strength and biological properties. Prepared samples are named as M: DAC5%, M: DAC10%, M: DAC15%and M: DAC20%. Where M is represented CH and OA. Equal amount of both polymers was used. Crosslinker % was with respect to polymeric matrix. HA and CU-HA are synthesized via the economical co-precipitation method. FT-IR and XRD analysis showed the successful synthesis of HA and Cu-HA. XRD analysis also confirmed the phase pure preparation of Cu substituted HA crystal There is no secondary phase appeared in XRD spectra of HA and Cu-HA. EDS results also supported copper substitution. Porous membranes for hard tissues regeneration were prepared by using prepared HA or Cu-HA with CS and OA. The freeze gelation method was used for the fabrication of membranes. These membranes are named as is M: HA and M: Cu-HA. Two bilayer membranes were prepared by using M: DAC15% as a first layer and second layer M: HA or ME: Cu-HA. These samples are name as Bi-MDAC%15-HA and Bi-MDAC%15-CuHA. The second layer was fabricated over the first layer. Physical and biological tests of the membranes were performed to evaluate the performance of prepared membrane samples.Item Phytochemical Loaded Functionally Graded Composite Regenerative Membrane for Potential Application of Osteochondral Regeneration(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-23) Sabahat Sultana Hashmi; FA19-R06-010; Dr. Sobia Tabassum; LHR TP 7312Osteochondral defect is the fourth main reason of hospitalization round the world and remains a challenge. Different medical treatments are available to cure osteochondral disease but because of limitation in their effectiveness including shortage of source of chondrocytes, difficulty in fixation, long time for harvesting and less effectiveness for old people, it is still challenging to regenerate both subchondral bone and cartilage together. Generally, bone grafts contribute towards the treatment purpose but this repairmen technique has many limitations that it can only helpful in segmental bone repairmen. Therefore, it is the need to develop effective and economical treatment for regeneration of both cartilage and subchondral bone. Functional, physiological and structural differences of osteochondral defects required functionally and structurally graded biomaterial for effective regeneration. In this study, a functionally and structurally graded composite membrane was prepared. For osteochondral regeneration, polyvinyl alcohol-based composite membranes are frequently utilized. To improve the biological performance of membranes varying amounts of PVA and less explored protein source (oval albumin) were used. The layer that facilitates cartilage regeneration was formed by crosslinking oval albumin with polyvinyl alcohol (PVA). Four different compositions of membranes for cartilage repair were prepared including OA-PVA-100, OA-PVA-80, OA-PVA-60, and OA-PVA-50. And the other layer for bone regeneration was fabricated by using 60% OA with respect to PVA, hydroxyapatite (HA) and sodium alginate was used as cross linker. Hard layer was name as OA-PVA-60-HA Freeze thaw method was used install porosity in membrane and to promote its regeneration capacity. HA is best widely used bone graft bio-mineral. In its composition and morphology it resembles to the subchondral tissue of bone. HA was prepared by in-situ Co-precipitation process. The bilayer was prepared in two basics steps. The first step involved the synthesis of membrane for subchondral regeneration with the same method for single layer preparation and then the cartilage layer was poured on it and cured at 60 °C. To further improve the biological performance and to install antibacterial properties in bilayer membrane, x samples were loaded with moringa plant extract.Item Preparation of Nature Mimicked Composite Materials for Tissue Regeneration(Library Information Services COMSATS University Islamabad Lahore Campus, 2020-02-20) Moiz U Din Khan; FA18-R06-018; Dr. Sobia Tabassum; LHR TP 6496Skeletal defect is the second largest reason that leads to disability in worldwide. The bone is the most common transplanted tissue after blood. Bone regeneration strategy remains a significant challenge in the treatment. The filling of the lesion is an important factor to evaluate regenerative ability of implant along with its bioactivity. Most of regenerative commercial approaches are not very practical to use. Their application in trauma site caused varied degrees of damage to normal tissues. Pre-formed scaffolds cannot fill irregular defects as good as in situ forming implant. In-situ formed implants received great attention as they provided ease of use along with excellent healing capacity. A thermosensitive in situ forming hydrogels are synthesized by crosslinking of Chitosan (CS), Zein (ZN) and Hydroxyapatite (HA). CS, ZN and HA are biocompatible, economical, and biodegradable materials, used in range of biomedical applications. HA is gold standard biomineral used for excellent regeneration of bone tissue. ZN is a good source of amino acids that can help in regeneration of collagen matrix of hard and soft tissues. CS is the second most abundant natural biopolymer having excellent ability to from thermosensitive hydrogels. The major challenge of in situ forming implants is relatively low mechanical strength. To improve the mechanical strength and biological performance ZN is used. HA is synthesized via economical co-precipitation method. CS/HA/ZN thermosensitive hydrogel of different composition CS.HA.ZN (0), CS.HA.ZN (25), CS.HA.ZN (50) CS.HA.ZN (75) CS.HA.ZN (100) are prepared. Changing the pH of CS solution gradually acidic to neutral converted it to gel phase. Appropriate reagents that gradually change the pH are used. Here very less explored calcium glycerophosphate (Ca.GP) is used. Ca.GP help is contains Calcium and phosphate groups that are also component of hard tissue so presence of this also facilitate regeneration. Thermo sensitive in situ forming hydrogels are prepared by optimizing by changing the amount of neutralizing agent’s and Ca.GP and sodium bicarbonate (NaHCO3). CS, ZN and HA solution in the presence of neutralizing agents at 10 -12 °C existed in solutions form and constituted to hydrogels setting at 37 °C in 6-7 minutes.Item A DFT Study of Dopamine Functionalized Borospherenes for Effective Cancer Treatment(Library Information Services COMSATS University Islamabad Lahore Campus, 2020-02-19) Iqra Karim; SP19-R06-003; Dr. Sobia Tabassum; LHR TP 6507Cancer has become one of the major threats to human life. Cancer therapies also bear the risk to health tissues. An effective approach to safe health cells is the integration of photothermal properties in the targeted chemotherapeutic system. In the present study, the targeted drug-carrying capacity of dopamine functionalized borospherene has been explored with the help of DFT. The results reveal that functionalization has a strong influence on geometrical, electronic, and thermodynamic properties of borospherene. The drug-loaded on functionalized borospherene has reduced the bandgap up to 2.104 eV. The reduction in band gap is fully supported by the density of states. The thermodynamic data confirms the exothermic and spontaneous nature of adsorption. NBO analysis confirms the charge transfer from drug and dopamine towards borospherene. Functionalization of dopamine extraordinarily increases the molecular descriptors parameters. The softness and electrophilicity index values increased for the drug-loaded on functionalized borospherene to 0.48 eV and 7.51 eV respectively. Similarly, the dipole moment also increases from 11.86 Debye to 21.94 Debye increasing the polarity. Moreover, the values of chemical hardness and chemical potential decrease from 1.45 eV to 1.05 eV and -3.71 eV to -3.97 eV respectively. This shows improved stability and reactivity of the functionalized borospherene than the drug load on pristine borospherene. All these are favorable drug delivery capacity of functionalized borospherene system. The SERS-Raman spectrum of functionalized borospherene shows more intense peaks at 1500-2000 cm- 1 and 3000-4000 cm-1 than the drug-loaded on pristine borospherene which has one intense peak at 1500-2000 cm-1. It means that functionalization improves the detection of the drug. Similarly, UV spectrum also shows that the maximum absorption increases from wavelength 501 nm to 581 after functionalization and a weak signal also appears at 703 nm.Item Computational Evaluation of Metal Doped Phosphorene-Nanosheets for Cancer Treatment(Library Information Services COMSATS University Islamabad Lahore Campus, 2020-02-19) Hira Karim; LHR TP 6508; Dr. Sobia Tabassum; LHR TP 6508Cancer is known as one of the leading causes of human mortality. The cancer treatments also damage the healthy tissue. So effective theranostic treatments are required for efficient cancer therapy and safety of healthy tissue. Phosphorene is a great material of interest to develop efficient targeted drug delivery system and imaging guided thermal therapy for cancer curing. Metal doping in a material is offered to tune its properties. In this work, effect of group II A metals on targeted delivery of anti-cancer drug, photoimaging (image guided cancer treatment) and photothermal treatment (thermal killing of cells by employing near infrared (NIR) light of doped phosphorene are evaluated via DFT method. The adsorption energies, quantum molecular properties, Atoms in Molecules (AIM) analysis, and Natural Bond Orbital (NBO) analysis of drug loaded pristine and doped phosphorene complexes were explored to understand the type of events in their interactions. The thermodynamic data confirms the exothermic and spontaneous nature of adsorption. The doped complexes showed better adsorption than pristine complex. The polarity was found to increase in doped complexes which is essential for driving in biological systems. Drug adsorption and doping have decreased the chemical potential and electrophilicity index while increased the softness of pristine phosphorene and doped phosphorene. The NBO data indicated the flow of charge from drug to nanosheet. Doping has made suitable the charge transfer and associated interaction. This interaction is strong in neutral pH. At acidic pH, in cancerous tissue environment drug will be protonated and will lose this interaction. These interactions were further investigated by Quantum Theory of Atoms in Molecules (QTAIM) analysis, revealing strong covalent interactions in all doped complexes except for one Mg-O bond in Mg-doped complex which owns strong electrostatic interactions. TD-DFT study showed lowering of band gap and shifting of λmax towards NIR region which is very useful for photothermal and image guided therapy. The Surface-Enhanced Raman Scattering (SERS) analysis revealed that doped systems effectively enhanced the Raman signals. All these properties supported the potential use of doped phosphorene complexes for photoimaging and photothermal killing of cancer cells.