Polymer Hydrogels
By Amit Gomey
U12CH026
Under the Guidance Of
Dr. A.K. Jana
Associate Professor
Svnit
Contents
• Polymer
• Hydrogel
• Classifications of hydrogels
• Technologies adopted in hydrogel preparations
• Drug Delive...
What is Polymer?
• The word polymer has been derived from the Greek words polys
(meaning many) and meros (Part or unit). T...
What is hydrogels?
Hydrogel products constitute a group of polymeric materials, the
hydrophilic structure viz. amino, carb...
Hydrogels
Hydrogels
Technical Features Of Hydrogels
• The highest absorption capacity in saline.
• Desired rate of absorption depending on the...
• The highest biodegradability without formation of toxic species
following the degradation.
• pH-neutrality after swellin...
Limitations
• High cost
• Low mechanical strength
• Can be hard to handle
• Difficult to load with drugs/nutrients
• May b...
Classification Of Hydrogels
Based on source:
(a) Natural and
(b) Synthetic
Based on polymeric composition:
(a) Homopolym...
Based On Configuration :
(a) Amorphous (non-crystalline).
(b) Semi-crystalline: A complex mixture of amorphous and crysta...
Based On Physical Appearance:
(a) Matrix
(b) Film
(c) Microsphere
Based on presence or absence of electrical charge loca...
Technologies Adopted In Hydrogel Preparation
The polymerization techniques have been listed below:
• Bulk Polymerisation
•...
Bulk Polymerisation
• Bulk hydrogels can be formed with one or more types of monomers.
• Usually, a small amount of cross-...
Solution Polymerisation
• In solution copolymerization/cross-linking reactions, the ionic or
neutral monomers are mixed wi...
Suspension Polymerization
• In this technique, the monomers and initiator are dispersed in the
hydrocarbon phase as a homo...
Grafting Polymerisation
• Done to add strength to structure of hydrogels as bulk
polymerisation give weak structured hydro...
UV Polymerisation
• Ionizing high energy radiation, like gamma rays and electron beams,
used as an initiator to prepare th...
Preparation
Following are the method for the synthesis of hydrogels:
• Synthesis of hydrogels from monomers
• Synthesis of...
Synthesis of hydrogels from monomers
• Copolymerization of hydrophilic monomers and polyfunctional
comonomers, acting as c...
Synthesis of hydrogels from prepolymers
• Prepared by crosslinkage of low molecular weight hydrophilic
polymers or oligome...
Synthesis of hydrogels from polymers
• Chemical cross linkage of hydrophilic polymers results in the
formation of a hydrog...
Drug Delivery
• Peroral Drug Delivery
• Drug Delivery in the Oral Cavity
• Drug Delivery in the GI Tract
• Rectal Delivery...
Applications
• Drug Delivery
• Cosmeteology
• Hydrogel for Gene Delivery
• Novel Hydrogel for Controlled Drug Delivery
• T...
• Cosmetology: Implanted into breast accentuate them for aesthetic
reasons. Implants have silicon elastomer shell and are ...
• Tissue Engineering: Micronized hydrogels used to deliver
macromolecules (phagosomes) into cytoplasm of antigen-presentin...
Conclusion
Hydrogels are an interesting class of materials that can be prepared by
a variety of methods. The properties of...
References
1. George A. Paleos, Pittsburgh Plastics Manufacturing, Butler, PA, What
are Hydrogels?
2. Iwona Gibas and Hele...
5. K. Pal, A. K. Banthia And D. K.Majumdar,Department Of Biotechnology &
Medical Engineering, National Institute Of Techno...
Thank You
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Polymer Hydrogels by Gomey
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Polymer Hydrogels by Gomey

Published on: Mar 4, 2016
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Transcripts - Polymer Hydrogels by Gomey

  • 1. Polymer Hydrogels By Amit Gomey U12CH026 Under the Guidance Of Dr. A.K. Jana Associate Professor Svnit
  • 2. Contents • Polymer • Hydrogel • Classifications of hydrogels • Technologies adopted in hydrogel preparations • Drug Delivery • Applications
  • 3. What is Polymer? • The word polymer has been derived from the Greek words polys (meaning many) and meros (Part or unit). The polymers (e.g. proteins and celluloses) form the basic building block of life. • Polymers are substances whose molecules have high molar masses and are composed of a large number of repeating units. There are both naturally occurring and synthetic polymers. Among naturally occurring polymers are proteins, starches, cellulose, and latex.
  • 4. What is hydrogels? Hydrogel products constitute a group of polymeric materials, the hydrophilic structure viz. amino, carboxyl and hydroxyl groups, in the polymer chains of which renders them capable of holding large amounts of water in their three-dimensional networks. The ability of hydrogels to absorb water arises from hydrophilic functional groups attached to the polymeric backbone, while their resistance to dissolution arises from cross-links between network chains.
  • 5. Hydrogels
  • 6. Hydrogels
  • 7. Technical Features Of Hydrogels • The highest absorption capacity in saline. • Desired rate of absorption depending on the application requirement. • The highest absorbency under load (AUL). • The lowest soluble content and residual monomer. • The highest durability and stability in the swelling environment and during the storage.
  • 8. • The highest biodegradability without formation of toxic species following the degradation. • pH-neutrality after swelling in water. • Colorlessness, odorlessness, and absolute non-toxic. • Photo stability. • Re-wetting capability (if required) the hydrogel has to be able to give back the imbibed solution or to maintain it; depending on the application requirement (e.g., in agricultural or hygienic applications).
  • 9. Limitations • High cost • Low mechanical strength • Can be hard to handle • Difficult to load with drugs/nutrients • May be difficult to sterilize • Non Adherent
  • 10. Classification Of Hydrogels Based on source: (a) Natural and (b) Synthetic Based on polymeric composition: (a) Homopolymeric hydrogels (b) Copolymeric hydrogels (c) Multipolymer interpenetrating polymeric hydrogel
  • 11. Based On Configuration : (a) Amorphous (non-crystalline). (b) Semi-crystalline: A complex mixture of amorphous and crystalline phases. (c) Crystalline. Based On Type Of Cross-linking: (a) Physical Nature and (b) Chemical Nature
  • 12. Based On Physical Appearance: (a) Matrix (b) Film (c) Microsphere Based on presence or absence of electrical charge located on the crosslinked chains (a) Nonionic (neutral) (b) Ionic (including anionic or cationic) (c) Amphoteric electrolyte (ampholytic) (d) Zwitterionic
  • 13. Technologies Adopted In Hydrogel Preparation The polymerization techniques have been listed below: • Bulk Polymerisation • Solution polymerization/cross-linking • Suspension polymerization • Grafting to a support • UV Polymerisation
  • 14. Bulk Polymerisation • Bulk hydrogels can be formed with one or more types of monomers. • Usually, a small amount of cross-linking agent is added in any hydrogel formulation. • The polymerization reaction is normally initiated with radiation, ultraviolet, or chemical catalysts. • High rate of polymerization and degree of polymerization occur because of the high concentration of monomer.
  • 15. Solution Polymerisation • In solution copolymerization/cross-linking reactions, the ionic or neutral monomers are mixed with the multifunctional crosslinking agent. • The polymerization is initiated thermally by UV-irradiation or by a redox initiator system. • The prepared hydrogels need to be washed with distilled water to remove the monomers, oligomers, cross-linking agent, the initiator, the soluble and extractable polymer, and other impurities
  • 16. Suspension Polymerization • In this technique, the monomers and initiator are dispersed in the hydrocarbon phase as a homogenous mixture. • The viscosity of the monomer solution, agitation speed, rotor design, and dispersant type mainly governs the resin particle size and shape. • The dispersion is thermodynamically unstable and requires both continuous agitation and addition of a low hydrophilic–lipophilic- balance (HLB) suspending agent.
  • 17. Grafting Polymerisation • Done to add strength to structure of hydrogels as bulk polymerisation give weak structured hydrogels. • Technique involves the generation of free radicals onto a stronger support surface and then polymerizing monomers directly onto it as a result a chain of monomers are covalently bonded to the support.
  • 18. UV Polymerisation • Ionizing high energy radiation, like gamma rays and electron beams, used as an initiator to prepare the hydrogels of unsaturated compounds. • Results in the formation of radicals on the polymer chains. • Recombination of the macro-radicals on different chains results in a cross-linked structure is formed.
  • 19. Preparation Following are the method for the synthesis of hydrogels: • Synthesis of hydrogels from monomers • Synthesis of hydrogels from prepolymers • Synthesis of hydrogels from polymers
  • 20. Synthesis of hydrogels from monomers • Copolymerization of hydrophilic monomers and polyfunctional comonomers, acting as crosslinkers, leads to the formation of hydrophilic network structures. • Commonly used monomers are hydrophilic (meth) acrylates and (meth) acrylamides. • Polymerization of vinyl monomers is most frequently initiated via radical initiators. By the use of redox initiator, radicals are generated.
  • 21. Synthesis of hydrogels from prepolymers • Prepared by crosslinkage of low molecular weight hydrophilic polymers or oligomers. • The reaction of α, ω-hydroxyl poly (ethylene glycol) with a diïsocyanate in the presence of a triol as crosslinker. • The reaction leads to the formation of crosslinked hydrophilic polyurethanes.
  • 22. Synthesis of hydrogels from polymers • Chemical cross linkage of hydrophilic polymers results in the formation of a hydrogel. • Preparation of stationary phases for gel filtration chromatography. • Other polymers like gelatine and agarose can form hydrogels upon cooling from an aqueous solution. The gel formation is due to helix- formation and association of the helices, forming junction zones
  • 23. Drug Delivery • Peroral Drug Delivery • Drug Delivery in the Oral Cavity • Drug Delivery in the GI Tract • Rectal Delivery • Ocular Delivery • Transdermal Delivery • Subcutaneous Delivery • Protein Drug Delivery
  • 24. Applications • Drug Delivery • Cosmeteology • Hydrogel for Gene Delivery • Novel Hydrogel for Controlled Drug Delivery • Tissue Engineering • Soft Contact Lenses
  • 25. • Cosmetology: Implanted into breast accentuate them for aesthetic reasons. Implants have silicon elastomer shell and are filled with hydroxyl propyl cellulose polysaccharide gel. • Hydrogel for Gene Delivery: Modification of hydrogel composition leads to effective targeting and delivery of nucleic acids to specific cells for gene therapy. • Novel Hydrogel for Controlled Drug Delivery: HYPAN is the novel hydrogel having properties useful for controlled drug delivery.
  • 26. • Tissue Engineering: Micronized hydrogels used to deliver macromolecules (phagosomes) into cytoplasm of antigen-presenting cells. This property is also utilized in cartilage repairing. Natural hydrogel materials used for tissue engineering include agarose, methylcellulose and other naturally derived products. • Soft Contact Lenses
  • 27. Conclusion Hydrogels are an interesting class of materials that can be prepared by a variety of methods. The properties of these materials depend on their building blocks and the preparation procedures and can be largely varied. They can be classified on the basis of source, cross-linking and configurations. Hydrogels serve a broad range of applications, including biomaterials, matrices for drug delivery and scaffolds for tissue engineering.
  • 28. References 1. George A. Paleos, Pittsburgh Plastics Manufacturing, Butler, PA, What are Hydrogels? 2. Iwona Gibas and Helena Janik, Gdansk University of Technology, Synthetic Polymer Hydrogels for Biomedical Applications, October 7, 2010 3. Enas M. Ahmed, Department of Chemical Engineering & Pilot Plant, National Research Centre, Dokki, Giza, Egypt, Hydrogel: Preparation, characterization, and applications: A review, 18 July 2013 4.E H Schacht, Department of Organic Chemistry, Polymer Materials Research Group, Egypt , Polymer chemistry and hydrogel systems, 2004
  • 29. 5. K. Pal, A. K. Banthia And D. K.Majumdar,Department Of Biotechnology & Medical Engineering, National Institute Of Technology, Rourkela, Polymeric Hydrogels: Characterization And Biomedical Applications –A Mini Review,2009 6. Syed K. H. Gulrez, Saphwan Al-Assaf and Glyn O Phillips,Glyn O Phillips Hydrocolloids Research Centre, Glyndwr University, Wrexham United Kingdom, Hydrogels: Methods of Preparation, Characterisation and Applications 7. Ritesh Kumar, Pawan Kumar Gautam, Amrish Chandra and Vijay Kumar Sharma, HYDROGELS- A NOVEL A ND SMART DRUG DELIVERY SYSTEM: AN UPDATED REVIEW,27 July 2014 8. http://www.kprblog.in/wp-content/uploads/2015/06/sol_tec3.gif 9. http://www.kprblog.in/wp-content/uploads/2015/06/mp_img1-300x260.gif
  • 30. Thank You

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