Recent Trend on Hydrogel

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Presentation gives an idea and all update on Hydrogel.


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On Hydrogel Presented By~ Miss Sarita M Nehatkar RECENT TREND 24/11/2011 1

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Quick View Introduction Properties of hydrogel Advantages Disadvantages Classifications Preparation methods of hydrogels Common uses for hydrogels Applications of hydrogels Products of hydrogel nano dox hydrogel Fucoidan-chitosan hydrogel Corgel biohydrogel Recent trends of hydrogel Patents References 24/11/2011 2

What is a Hydrogel?:

What is a Hydrogel ? “ Hydrogel is a network of polymer chains that are water-insoluble, sometimes found as a colloidal gel in which water is the dispersion medium.” 24/11/2011 3


PROPERTIES OF HYDROGEL Tendency to imbibe water. Ability to swell. An ideal material for use in drug delivery and immobilization of proteins, peptides, and other biological compounds. Due to their high water content, these gels resemble natural living tissue. 24/11/2011 4

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Hydrogel : Swellable Polymeric Materials Hydrogels are three dimensional networks of hydrophilic polymers. Extremely absorbent and possess a degree of flexibility very similar to natural tissue . Drug encapsulated in a hydrogel matrix is only released after contact with organ-or tumor -specific molecules (e.g. surface proteins).


ADVANTAGES Biocompatible Can be injected Easy to modify Timed release of growth factors and other nutrients to ensure proper tissue growth Entrapment of microbial cells within polyurethane hydrogel beads with the advantage of low toxicity Environmentally sensitive hydrogels have the ability to sense changes of pH, temperature or the concentration of metabolite and release their load as result of such a change. Natural hydrogel materials are being investigated for tissue engineering, which include agarose,methylcellulose , hylaronan , and other naturally derived polymers. 24/11/2011 6

ADVANTAGES (contd.):

ADVANTAGES (contd.) Absence of Phagocytosis by macrophages 24/11/2011 7


DISADVANTAGES The main disadvantages are the high cost and the sensation felt by movement of the maggots. Its disadvantage include surgical risk associated with the device implantation and reterieval . Hydrogels are nonadherent ; they may need to be secured by a secondary dressing. Disadvantages of hydrogel in contact lenses are lens deposition , hypoxia , dehydration and red eye reactions . 24/11/2011 8


CLASSIFICATIONS Diffusion-Controlled Release Systems Reservoir Systems. Matrix Systems Swelling-Controlled Release Systems Chemically Controlled Release Systems Erodible drug delivery systems Pendent chain systems Environmentally Responsive systems pH sensitive Hydrogel Temprature sensitive hydrogels Complexing Hydrogele Sensitive to chemical or enzymatic reaction Magnetically responsive systems 24/11/2011 9

Mechanism of Stimuli Responsive Hydrogels:

Mechanism of Stimuli Responsive Hydrogels 24/11/2011 10

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24/11/2011 11

Classification On the basis of origin:

Classification On the basis of origin 24/11/2011 12


1)Chemically crosslinked gels In this method chemically crosslinked gels are formed by radical polymerization of low molecular weight monomers, or branched homopolymers , or copolymers in the presence of crosslinking agent. This reaction is mostly carried out in solution for biomedical applications Copolymerization/ Crosslinking Reactions: - Copolymerization reactions are used to produce polymer gels, many hydrogels are produced in this fashion, for example poly ( hydroxyalkyl methylacrylates ). PREPARATION METHODS Of HYDROGELS 24/11/2011 13


Contd.. Crosslinking by High Energy Radiation: - High energy radiation, such as gamma and electron beam radiation can be used to polymerize unsaturated compounds.Water soluble polymers derivatized with vinyl groups can be converted into hydrogels using high energy radiation. Crosslinking Using Enzymes: - Recently a new method was published using an enzyme to synthesize PEG-based hydrogels . A tetrahydroxy PEG was functionalized with addition of glutaminyl groups and networks were formed by addition of transglutaminase into solution of PEG and poly (lysine- cophenylalanine ) 24/11/2011 14

2)Physically crosslinked gels:

2)Physically crosslinked gels Cross-linking by Ionic interactions An example of cross-linking via ionic interactions is cross-linking of Alginate consists of glucuronic acid residues and mannuronic residues and can be cross-linked by calcium ions. Cross-linking can be carried out at normal temperature and pH. These gels are used as matrix for encapsulation of cells and for release of proteins. Chitosan based hydrogels,as well as dextran based hydrogels , cross-linked with potassium ions also other gels synthesized with ionic interactions. Cross-linking by Crystallization An aqueous solution of PVA that undergoes a freeze-thaw process yiels a strong highly elastic gel. Gel formation is attributed to the formation of PVA crystallites which act as physical cross-linking sites in the network. The gel properties could be modified by varying polymer concentration, temperature, and freezing and thawing cycle times. These gels have been shown to be useful for drug release. 24/11/2011 15


Contd.. Cross-linking by hydrogen Bonds Poly(acrylic acid) and poly( methacrylic acid) form complexes with poly(ethylene glycol) by hydrogen bonding the oxygen of the poly(ethylene glycol) and the carboxylic acid group of poly( methacrylic acid). Cross-linking by Protein Interaction Genetic engineering has also been used for the preparation of hydrogels . The major advantage is that the sequence of peptides and, therefore its physical and chemical properties can be precisely controlled by the proper design of the genetic code in synthetic DNA sequences. Ag- Ab crosslinking . 24/11/2011 16


COMMON USES FOR HYDROGELS Currently used as scaffolds in tissue engineering. When used as scaffolds, hydrogels may contain human cells in order to repair tissue. Environmentally sensitive hydrogels.These hydrogels have the ability to sense changes of pH, temperature, or the concentration of metabolite and release their load as result of such a change. As control-release delivery systems 24/11/2011 17


Contd.. Provide absorption, desloughing and debriding capacities of necrotics and fibrotic tissue. Hydrogels that are responsive to specific molecules, such as glucose or antigens can be used as biosensors as well as in DDS. Used in disposable diapers where they "capture" urine. Contact lenses (silicone hydrogels,polyacrylamides ). 24/11/2011 18

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Factors affecting the drug release from Hydrogels


APPLICATIONS OF HYDROGELS Applications of Hydrogels in Drug Delivery Drug Delivery in the GI Tract: - The ease of administration of drugs and the large surface area for absorption makes the GI tract most popular route for drug delivery. Hydrogel -based devices can be designed to deliver drugs locally to specific sites in the GI tract. 24/11/2011 20

Rectal Delivery:

Rectal Delivery This route has been used to deliver many types of drugs for treatment of diseases associated with the rectum, such as hemorrhoids. This route is an ideal way to administer drugs suffering heavy first-pass metabolism. An indomethacin poly vinyl alcohol (PVA) hydrogel used for rectal administration. The release of indomethacin from the PVA hydrogel agreed with the Fickian diffusion model for 10 hr. Rectal administration of indomethacin hydrogels to rats yielded high indomethacin plasma concentrations, without producing a sharp peak, and a sustained-release effect. In dogs, the indomethacin hydrogel produced a similar sustained-release effect; however, the indomethacin plasma concentration was relatively low compared with that of an indomethacin suppository. 24/11/2011 21

Ocular Delivery:

Ocular Delivery Drug delivery to the eye is difficult due to its protective mechanisms, such as effective tear drainage, blinking, and low permeability of the cornea. Thus, eye drops containing drug solution tends to be eliminated rapidly from the eye and the drugs show limited absorption, leading to poor ophthalmic bioavailability. Due to the short retention time, a frequent dosing regimen is necessary for required therapeutic efficacy. 24/11/2011 22

Transdermal Delivery:

Transdermal Delivery Polyurethane hydrogel drug reservoirs for use in transdermal drug delivery systems. A drug reservoir for use in a transdermal drug delivery system, comprising a layer of a polyurethane hydrogel having a drug formulation comprising at least one permeation enhancer absorbed therein. Drug delivery to the skin has been generally used to treat skin diseases or for disinfections of the skin. 24/11/2011 23

Wound healing :

Wound healing A modified polysaccharide that occurs in cartilage has been used in formation of hydrogels to treat cartilage defects has been developed ( Fenglan et al., 2004). Honey hydrogels have been used for 1180 Sci. Res. Essays prompt wound healing. These hydrogels have matrix in which honey is cross-linked and most acceptable, easily peeled, and transparent system ( Yusof et al., 2007). The hydrogel of gelatin and PVA (polyvinyl alcohol) along with blood coagulant have been formulated. The cell adhesive hydrogel ensured better effect than corresponding gel or ointment in controlling blood coagulation ( Mukherjee and Banthia , 2006). 24/11/2011 24

Industrial applicability :

Industrial applicability Hydrogels have been used as absorbents for industrial effluents like methylene blue dye ( Paulino et al., 2006). The other example is the adsorption of dioxins by hydrogel beads. The DNA of Salmon milt adsorbs dioxins which produce health hazards like carcinogenicity,immunotoxicity or endocrine disruption. 24/11/2011 25

Miscellaneous applications:

Miscellaneous applications Hydrogels are also used in other forms of drug delivery like pulsatile drug delivery or oral drug delivery (He et al., 2008a; Guo and Gao, 2007; Gazzaniga et al., 2008). Injectable hydrogels are also been investigated for cancer drug delivery. In situ gel-forming hydrogels for prolonged duration have also been reported (Ta et al.,2008; Fang et al., 2008). 24/11/2011 26

Application of Hydrogels to Fix Bone Replacements :

Application of Hydrogels to Fix Bone Replacements Provided are orthopedic fasteners and replacements such as nails, screws, pins and knee replacements, etc., coated with hydrogels and other biocompatible/biodegradable materials which expand in the presence of liquids. Useful coating materials include methacrylate , hyaluronic acid esters, and crosslinked esters of hyaluronic acid resulting from the esterification of hyaluronic acid with polyhydric alcohols Replacements can be thus coated, even those made of stainless steel, metal alloys, titanium, or cobaltchromium , treatment of the surfaces to improve metal-polymer adhesion. 24/11/2011 27

Hydrogel for Repairing, Regenerating Human Tissue:

Hydrogel for Repairing, Regenerating Human Tissue Regenerating healthy tissue in a cancer-ridden liver, healing a biopsy site and providing wounded soldiers in battle with pain-killing, infection fighting medical treatment are among the myriad uses the scientists foresee for the new technology. 24/11/2011 28

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Delivery of bioactive molecules in Bone and Cartilage tissue Cartilage is a dense and fibrous connective tissue composed of an extracellular matrix (ECM) that contains collagen type II, proteoglycans , and water. Functions of Cartilage : Absorbing impact forces, Transferring load to the underlying bone, and Allowing low-friction movement of the joint. Articular cartilage


PRODUCTS OF HYDROGEL NANO DOX HYDROGEL NanoDOX ™ Hydrogel , the company's leading pharmaceutical product in development, is an alternative topical formulation of doxycycline . "Diabetic ulcers are the primary cause of amputations of the leg, foot, or toe. Two-thirds of all lower extremity . We believe that NanoDOX ™ is a unique formulation that holds significant promise for the millions of people suffering from diabetic ulcers," said Weaver H. Gaines, Chairman of the Board. " Nanotherapeutics developed the product with its proprietary particle stabilization technology and formulated it to improve the topical delivery of doxycycline to increase local efficacy of the drug. 24/11/2011 30


FUCOIDAN-CHITOSAN HYDROGEL Hydrogels are ideal biopolymeric pharmaceutical forms for the treatment of skin Wounds. They have low interfacial tension, high molecular and oxygen permeability , good moisturizing and mechanical properties that resemble physiological soft tissue. Low gel hardness ensures that the minimum work is required for removal of gels from the container and the applicability onto the desired site. 24/11/2011 31


CORGEL BIOHYDROGEL The patented hyaluronan ( hyaluronic acid) based biocompatible hydrogel is based on di hydroxyphenyl linkages of tyramine substituted hyaluronan . Corgel ™ may be useful in surgical and transcatheter applications including vascular surgery, cardiology, ophthalmology, orthopedics,aesthetics , ENT, drug delivery, tissue engineering and regenerative medicine 24/11/2011 32


RECENT TRENDS OF HYDROGEL The new type of hydrogel system HYPAN (which is known under the trademark Hypan ) is described in some detail here, emphasizing its grades and those properties potentially useful in controlled drug delivery systems. A physical network of crystalline clusters, which fully replace the covalent network typical of other hydrogels,distinguishes HYPAN hydrogels . As a result,HYPAN hydrogels can be processed by a number of methods unusual for hydrogels , such as extrusion and injection molding. The crystalline network also provides HYPAN with improved mechanical properties at higher water contents, which in turn allows for higher permeabilities of aqueous solutes. The combination of improved mechanical properties and permeabilities with improved processability and good biocompatibility is believed to open some new possibilities in targeted and controlled drug delivery. 24/11/2011 33

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Recent developments in the field of polymer science and technology has led to the development of various stimuli sensitive hydrogels like pH, temperature sensitive, which are used for the targeted delivery of proteins to colon, and chemotherapeutic agents to tumors. Some environmental variables, such as low pH and elevated temperatures, are found in the body. For this reason, either pH-sensitive and/or temperature sensitive hydrogels can be used for site-specific controlled drug delivery. 24/11/2011 34

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Hydrogels that are responsive to specific molecules, such as glucose or antigens, can be used as biosensors as well as drug delivery systems. 24/11/2011 35

Novelty of this hydrogel technology :

Novelty of this hydrogel technology There are two types of hydrogels currently in use: ► Bulk Hydrogels – the original hydrogel made of a polymer network. ► Superporous Hydrogels – a bulk hydrogel that has been forced into a “ swiss cheese” structure by adding freezing or acidity during formation . Advantages over bulk hydrogels : 100x faster responsiveness Encapsulation possibilities for larger molecules Bulk hydrogels are more appropriate for “controlled release”applications while hydrogel scaffolds are for “fast action.” Advantages over superporous hydrogels : Simpler formation process Faster uniform responsiveness Small size of microgels limits diffusion required Defined structure yields predictable response. Size flexibility 24/11/2011 36


PATENTS 24/11/2011 37


References CHARACTERIZATION OF POLYETHYLENE GLYCOL HYDROGELS FOR BIOMEDICAL APPLICATIONS A Thesis in The Department of Chemical Engineering by Anushree Datta B.E. University of Pune , India, 2005 August 2007. M. Zendehdel, Z. Kalateh, H. Alikhani EFFICIENCY EVALUATION OF NaY ZEOLITE AND TiO 2 / NaY ZEOLITE IN REMOVAL OF METHYLENE BLUE DYE FROM AQUEOUS SOLUTIONS Iran. J. Environ. Health. Sci. Eng., 2011, Vol. 8, No. 3, pp. 265-272 D.Mukherjee & A. K. Banthia Preparation of Adrenochrome Hydrogel Patch, Gel, Ointment, and the Comparison of Their Blood Coagulating and Wound Healing Capability, Materials and Manufacturing Processes ,Volume 21, Issue 3, 2006, pages 297-301 Ximena Viala and Fotios M. Andreopoulos Novel Biomaterials for Cartilage Tissue Engineering Current Rheumatology Reviews, 2009, 5, 51-57 24/11/2011 38

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Saima Amin Hydrogels as potential drug delivery systems Scientific Research and Essay Vol. 3 (11), pp. 1175-1183, November, 2009 Vijay Singh Jatav Recent Trends on Hydrogel in Human Body International Journal of Research in Pharmaceutical and Biomedical Sciences Vol. 2 (2)pp.442-447, Apr – Jun 2011 Mohammad Reza Saboktakin Hydrogels as Potential Nano -Scale Drug Delivery Systems, Biopolymers,pp.575-596. Kevin Brounstein , Highly Responsive Hydrogel Scaffold, Boston, MA Anisha Singh1 HYDROGELS: A REVIEW International Journal of Pharmaceutical Sciences Review and Research Volume 4, Issue 2, Article 016 ,pp97-105,September – October 2010; Jin-Oh You Bioresponsive matrices in drug delivery Journal of Biological Engineering , 4:15 doi:10.1186/1754-1611-4-15, 2010 CS Satish Hydrogels as controlled drug delivery systems: Synthesis, crosslinking , water and drug transport mechanism, ijps Volume : 68  |  Issue : 2 Page : 133-140, Year : 2006 24/11/2011 39

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Thank You..! 24/11/2011 40 Miss Sarita M. Nehatkar M.Pharm II (QA) Govt. College Of Pharmacy,Amravati .

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