Báo cáo được tác giả thực hiện tại Trường Đại học Bách khoa TPHCM, môn Các hệ dẫn truyền thuốc (Drug Delivery Systems). Bài viết mô tả chi tiết các đặc điểm của hệ dẫn truyền Hydrogels, một hệ dẫn truyền thuốc phổ biến hiện nay trong lĩnh vực y khoa. Những đặc điểm của hydrogels, phương pháp tổng hợp hydrogels, phương pháp load thuốc và giải phóng thuốc khỏi hệ hydrogels được giải thích cụ thể. Hơn nữa, các phương pháp phân tích một hệ hydrogels và những ứng dụng của nó cũng được đề cập có trình tự. Tài liệu được viết bằng Tiếng Anh dễ đọc, dễ hiểu, sẽ là tài liệu tham khảo hay cho các bạn đang học sau đại học và những bạn quan tâm đến hệ dẫn truyền hydrogels.
SEMINAR REPORT OF DRUG DELIVERY SYSTEMS Topic: Hydrogels as Drug Delivery Systems Reporter: Nguyen Van Tu Supervisor: Dr Le Thanh Dung Dr Ha Cam Anh - 51305919 HCM city, October, 2014 HOOK INTRODUCTION Various Systems to be applied Attract much attention DDSs Hydrogels: worth concerning Each System possesses particular characteristics DDSs: Drug Delivery Systems SOME FIGURES The total number of papers on hydrogels from 1950 to 2011 was 43 764 Of these, 8554 references were on the topic of drug delivery In the drug delivery topic, the search for subtopics of proteins and genes resulted in 1674 and 284 references, respectively - S C Lee, I K Kwon and K Park, Adv Drug Delivery Rev., 2013,65,17–20 OUTLINE 1- GENERALITIES OF GELS AND HYDROGELS – FUNDAMENTAL CONCEPTIONS 2- STRUCTURES OF HYDROGELS – TOWARDS BEING USED 3- THE SYSTHESIS OF HYDROGELS, WAYS TO LOAD DRUGS INTO HYDROGELS AND THE RELEASE OF DRUGS FROM HYDROGELS 4- MEANS OF ANALYSIS OF STRUCTURES AND EFFECTIVE LOADINGS 5- POSIBILITIES OF APPLICATION 6- INCLUSION I VIEW OF GELS AND HYDROGELS – FUNDAMENTAL CONCEPTIONS 1.1 What is gel? Coined by 19th-century Scottish Chemist Thomas Graham is a solid, jelly-like material that can have properties ranging from soft and weak to hard and tough Gels are defined as a cross-linking system, which exhibits no flow when in the steady-state By weight, gels are mostly liquid, yet they behave like solids due to a three-dimensional cross-linked network within the liquid http://en.wikipedia.org/wiki/Gel I VIEW OF GELS AND HYDROGELS – FUNDAMENTAL CONCEPTIONS 1.1 What is gel? The solid is the continuous phase and the liquid is the discontinuous phase http://en.wikipedia.org/wiki/Gel I VIEW OF GELS AND HYDROGELS – FUNDAMENTAL CONCEPTIONS 1.2 What is hydrogel? Is a Gel in which the swelling agent is water (water is discontinuous phase) The network component of a hydrogel is usually a polymer network A hydrogel in which the network component is a colloidal network may be referred to as an Aquagel http://en.wikipedia.org/wiki/Gel http://www.gcsescience.com/o70.htm I VIEW OF GELS AND HYDROGELS – FUNDAMENTAL CONCEPTIONS 1.2 What is hydrogel? A hydrogel is an example of a smart material It can change structure in response to salt concentration, pH and temperature http://en.wikipedia.org/wiki/Gel http://www.gcsescience.com/o70.htm I VIEW OF GELS AND HYDROGELS – FUNDAMENTAL CONCEPTIONS 1.2 What is hydrogel? Hydrogels are 3D hydrophilic macromolecular networks (matrices) that are capable of retaining a large amount of water Having been used in a variety of applications, such as wound dressings, transdermal patches, drug delivery devices, contact lenses, or in reconstructive surgery Repeating unit of LBG, Xanth, and a photograph of the obtained physical gel - European Biophysics Journal 2007 Vol: 36(7):693-700 DOI: 10.1007/s00249-007-0158-y - Expert Rev Med Devices 4(2), 147-164 (2007) DOI: 10.1586/17434440.4.2.147 I VIEW OF GELS AND HYDROGELS – FUNDAMENTAL CONCEPTIONS 1.3 Major definitions Cross-link - A cross-link is a bond that links one polymer chain to another They can be covalent bonds or ionic bonds… "Polymer chains" can refer to synthetic polymers or natural polymers Cross-links - http://en.wikipedia.org/wiki/Cross-link Vulcanization with sulfur 10 IV MEANS OF ANALYSIS OF STRUCTURES AND EFFECTIVE LOADINGS 4.2 Focussing on analysis of structures 4.2.3 Ultravillet (UV) analysis Determining the amount of drug adsorbed onto hydrogels (effective adsorption) Goals Specifying the quantity of drug released from hydrogels in different media - J Mater Sci: Mater Med (2008) 19:2771–2780 DOI 10.1007/s10856-008-3406-5 - J Radioanal Nucl Chem DOI 10.1007/s10967-014-3514-2 - Journal of Biomaterials and Nanobiotechnology, 2011, 2, 36-40 DOI:10.4236/jbnb.2011.21005 53 IV MEANS OF ANALYSIS OF STRUCTURES AND EFFECTIVE LOADINGS 4.2 Focussing on analysis of structures 4.2.3 Ultravillet (UV) analysis - N.A Peppas et al / Journal of Controlled Release, 62 (1999) 81–87 54 IV MEANS OF ANALYSIS OF STRUCTURES AND EFFECTIVE LOADINGS 4.2 Focussing on analysis of structures 4.2.4 Thermogravimetric analysis (TGA) Studying thermostability of hydrogels Objectives Measuring the compositions of hydrogels - J Radioanal Nucl Chem DOI 10.1007/s10967-014-3514-2 55 IV MEANS OF ANALYSIS OF STRUCTURES AND EFFECTIVE LOADINGS 4.2 Focussing on analysis of structures 4.2.4 Thermogravimetric analysis (TGA) - J Radioanal Nucl Chem DOI 10.1007/s10967-014-3514-2 56 V POSIBILITIES OF APPLICATION 5.1 View of applications In recent years, there has been remarkable process in the development of clinically applied hydrogels Since 1960, the copolymers of 2-(HEMA) and ethylene dimethacrylate have been applied for their use in contact lens, urinary catheters, wound dressing and surgical gloves, etc After that, development of clinically applied hydrogels has attracted research regards - Journal of Materials Chemistry B, 2014, 2, 147-166 57 V POSIBILITIES OF APPLICATION 5.1 View of applications - Journal of Materials Chemistry B, 2014, 2, 147-166 58 V POSIBILITIES OF APPLICATION 5.1 View of applications - Journal of Materials Chemistry B, 2014, 2, 147-166 59 V POSIBILITIES OF APPLICATION 5.2 Some of specific applications Implanting degradable insulin loaded-poly(NIPAAm- co-Dex-lactateHEMA) hydrogels to rat’s conjunctiva for treating diabetic retinopathy - G.P Misra et al / Biomaterials 30 (2009) 6541–6547 60 V POSIBILITIES OF APPLICATION 5.2 Some of specific applications Results of research demonstrated that both hydrogels and their degradation products were non-toxic to cultured R28 retinal cells, and accordingly the hydrogels have potential for in vivo implantation None of inflammation or morphological changes in eyes implanted insulin loaded hydrogels - G.P Misra et al / Biomaterials 30 (2009) 6541–6547 61 V POSIBILITIES OF APPLICATION 5.2 Some of specific applications Investigating starPEG-heparin-based hydrogels loaded by some Growth Factors (GFs): bFGF and EGF Applying to treat acute kidney injury on mice The results confirm possitive indication to ultilizing hydrogels for GFs delivery - M.V Tsurkan et al / Journal of Controlled Release 167 (2013) 248–255 62 V POSIBILITIES OF APPLICATION 5.2 Some of specific applications - M.V Tsurkan et al / Journal of Controlled Release 167 (2013) 248–255 63 V POSIBILITIES OF APPLICATION 5.2 Some of specific applications No visual signs of inflammation for both the control and the GFs treated mice The hydrogels alone did not induce treatment efficency There was the difference of proliferation between the left injected GF and the right non-injected GF kidney - M.V Tsurkan et al / Journal of Controlled Release 167 (2013) 248–255 64 V POSIBILITIES OF APPLICATION 5.3 Some drawbacks of hydrogels in DDSs May release toxic subtances Low mechanical strength ->limits load bearing Hydrogels Moist -> sterility, shipping, packing Some risks of infection, delayed wound healing - Journal of Materials Chemistry B, 2014, 2, 147-166 65 VI SUMMARY Hydrogels are considered one of drug delivery systems which has crucial position in medical applications There has been a great number of researches related to hydrogels, which aims to apply to target diseases on the majority of human body Besides advantages, hydrogels also have some drawbacks requiring the advance of design of hydrogels’ properties 66 Good day 67 ... THE SYSTHESIS OF HYDROGELS, THE WAYS TO LOAD DRUGS INTO HYDROGELS AND THE RELEASE OF DRUGS FROM HYDROGELS 3.1 Preparations of hydrogels Hydrogels Natural hydrogels Synthetic hydrogels Natural... SYSTHESIS OF HYDROGELS, THE WAYS TO LOAD DRUGS INTO HYDROGELS AND THE RELEASE OF DRUGS FROM HYDROGELS 3.1 Preparations of hydrogels Especially, Natural hydrogels Synthetic hydrogels Hydrogels... III THE SYSTHESIS OF HYDROGELS, THE WAYS TO LOAD DRUGS INTO HYDROGELS AND THE RELEASE OF DRUGS FROM HYDROGELS 3.1 Preparations of hydrogels 3.1.1 Physical cross-linking Hydrogels obtained are