This work is concerned with synthesis of multiresponsive smart copolymer hybrid microgels and polymer drug conjugates. Work can be divided in to two parts. In first part, we have synthesized both cationic and anionic hybrid microgels. Cationic pure NIsopropylacrylamide and vinyl imidazole copolymer, P(NIPAM-co-VI), microgels with different amount of vinyl imidazole were synthesized by free radical emulsion polymerization. Then, the hybrid microgels, P(NIPAM-co-VI)-Ag, was prepared and their thermal and pH dual responsive properties were studied. Thermogravimetric analysis were also carried out for the amount of metal content, and a maximum content 51.8% was obtained for P(NIPAM-co-VI)-3-Ag. The pH and thermos-responsive behavior was also analyzed for surface plasmon resonance using uv-visible spectroscopy. All the hybrid microgels could be stably dispersed in water at a pH range from 3.0 to 9.3, which is favorable to use p(NIPAM-co-VI)-Ag as a catalyst in the reduction reaction of p-nitrophenol. The highest reaction rate constant (kapp) value 4.49×10-3 sec-1 was observed for p(NIPAM-co-VI)-3-Ag at pH 2.95. Reaction rate was dependent on pH of the medium and the content of 1-VI in the copolymer microgels. We have also prepared anionic copolymer microgels based on thermal NIPAM and pH sensitive MAA. In-situ reduction method was used to prepare silver and gold hybrid microgels at two different pH’s. The surface charge involved in the change of particle size, was confirmed by calculating zeta potential values at different pH’s using dynamic light scattering. The prepared hybrid microgels were used as a catalyst for the reduction of p-nitrophenol to p-aminophenol. Our results shows that the p(NIPAM-co-MAA)s-Au catalysts are more efficient as compared to p(NIPAM-co-MAA)s-Ag. In the second part, we have synthesized a novel redox-responsive polymer–drug conjugate (PDC) based on hydrophilic diblock copolymer covalently bonded with paclitaxel (PTX) by a disulfide linker, and evaluated it for intracellular drug delivery. The well-defined hydrophilic diblock copolymer, PEG-b-PHEMA, was synthesized via atom transfer radical polymerization of 2-(trimethylsilyloxyl)ethyl methacrylate (HEMA-TMS), using PEG-Br as a macroinitiator and CuBr/PMDETA as the catalytic system, followed by selectively hydrolyzing the trimethylsilane group to hydroxyl groups. Utilizing the hydroxyl groups as an active reaction site, paclitaxel was covalently conjugated onto the backbone of the diblock copolymer, with a disulfide linker as a spacer to bridge the copolymer and PTX, and the loading content of paclitaxel was 18.4 wt%. Due to the different solubility of segments in the polymer–drug conjugate, the amphiphilic PEG-b-P(HEMA-PTX) could self-assemble into spherical micelles in aqueous solution, with hydrophobic PTX as core and hydrophilic PEG chains as shell. The in vitro cytotoxicity experimental results shows that the diblock copolymer is biocompatible, with no obvious cytotoxicity, whereas the PEG-b-P(HEMA-PTX) conjugate showed glutathione-dependent cytotoxicity with higher cellular proliferation inhibition against glutathione monoester pretreated HeLa cells than that of the nonpretreated HeLa cells. We are convinced that polymer–drug conjugates based on disulfide linkers will be a promising platform for targeted intracellular controlled drug delivery in cancer therapy.
ڈینگی ایک چیلنج نحمدہ وَ نُصَلِّیْ علی رسولہ الکریم امّا بعد فاعوذ بااللہ من الشیطن الرجیم بسم اللہ الرحمن الرحیم صدرِذی وقار معزز اسا تذہ کرام اور میرے ہم مکتب ساتھیو! آج مجھے جس موضوع پر لب کشائی کی سعادت حاصل کرنی ہے وہ ہے:’’ڈینگی ایک چیلنج،، جنابِ صدر! آج کل پورے پاکستان میں جس بیماری نے پاکستانیوں کے اعصاب کو مضمحل کر رکھا ہے وہ ڈینگی ہے اور ڈینگی بخار ہی کی ایک قسم ہے، چھوٹے، بڑے، امیر ،غریب ، کالے، گورے سب اس سے خوفزدہ ہیں ، سب اس سے فرار کا رستہ اختیار کرنے کے متمنی ہیں، اس کے نام سے ہی رونگٹے کھڑے ہوجاتے ہیں۔ صد رِمحترم! فرمان ِباری تعالیٰ ہے ’’کہ ایّا م لوگوں کے درمیان ایک جیسے نہیں رہتے، بدلتے رہتے ہیں۔ ‘‘ وقت کا دھارا گزر جاتا ہے۔ خزاں کے ختم ہوتے ہی بادِ بہاری کو اٹھکیلیاں سوجھنا شروع ہو جاتی ہیں۔ مردہ پتے گرنے لگتے ہیں، اورنئے شگو فے کھلنا شروع ہو جاتے ہیں،چمنستانِ ہستی میں بہار آ جاتی ہے، ستاروں کی گردش، اور زمین کی حرکت ارضی اور سماوی تبدیلیوں کی نشاندہی کرتی ہے۔ اے ہم نشیں ! کلام میرا لا کلام ہے سُن! زندگی تغیّرِ پیہم کا نام ہے صدرِذی وقار! انسان پر بھی حالات ایک جیسے نہیں رہتے،کبھی مسرت و شادمانی کی کیفیت ہوتی ہے، کبھی غم اور اندوہ ساتھ نبھانے کا تہیہ کر لیتے ہیں، کبھی امارات کے بادل سایہ فگن ہو جاتے ہیں، کبھی غربت و افلاس کی چکی میں پسنا مقدر بن جاتاہے۔ کبھی بیماری کا بھیانک چہرا جیسے ڈینگی کی صورت میں سامنے آتا ہے دیکھنا پڑتا ہے اورکبھی تندرستی اور صحت کی نوید جانفرا سنائی دینا شروع کر دیتی ہے۔ جنابِ صدر! انسان اشرف مخلوقات پیدا فرمایا گیا ہے۔ اس کونشیب و فراز سے واسطہ...
Religion Islam has given equal rights to men and women in the field of education. For men education was compulsory and women were encouraged to seek education. Both males and females have been referred to using polygamous section for education while women are often encouraged and especially emphasized. The Prophet(SAW)arranged special seats for the gender critical in order to highlight the importance of women education. That was way the passion for special education in women grew so much that women discussed global issues with men and solved to reject men’s judgement. It was the influence of this academic moment that many Muslim women not only made a name for themselves, but also wrote books on various research topic in the field of Hadith, Commentary, Iftaa and many other Sciences. Thanks for this global revolution Muslim rulers not only provided a learning environment for their children but also established large educational institutions for ordinary women. The astonishing thing is that despite this wonderful past today Muslims are unable to provide a safe and secure opportunity for education to women.
The main aim of this thesis is to present the numerical investigation of couple stress fluid in bounded and semi-bounded domains. The theory of couple stresses first introduced by Stokes, explain the rheological behavior of various complex non Newtonian fluids which preserves couple stresses and body couples and represents the simplest generalization of the classical fluid theory. Such flows have promising applications in engineering, bio-medical and chemical industries, for example, continuous stretching of plastic films, artificial fibers, metal extrusion, metal spinning, glass blowing, continuous casting,the extrusion of a polymer sheet from a die, the drawing of plastic films, etc. The efforts have been made to analyze the flow of couple stress fluid flowing over various possible flow situations, such as stretching sheet, porous shrinking sheet, two dimensional and axisymmetric flow over moving plate, off centered rotating disk, etc. The problems varies by considering effect of a magnetohydrodynamics (MHD), chemical reactions, stagnation point and partial slip condition on the flow. The heat transfer effects in the flow over stretching sheet would also be examined for the two heating processes, PST (prescribed surface temperature case) and PHF (prescribed heat flux case). The non-perturbative methods and Runge-Kutta method coupled with shooting technique have been implemented to obtain the solutions of considered problems.Moreover, some other flow problems of this kind of fluid will also be considered.