Novel Photocrosslinkable Hyperbranched Polymers for Injectable Scaffolds: Design, synthesis, characterisations and in vitro evaluation

Lead Research Organisation: Bangor University
Department Name: Sch of Chemistry

Abstract

Injectable scaffolds can offer the possibility of homogeneously distributing cells and molecular signals throughout the scaffold, and can be injected directly into cavities with irregular shape and size. Most studies have been on the development of injectable scaffolds for bone and cartilage tissue repair, some others for corneal wound healing. The most challenging issue is to find suitable materials which can solidify in situ to form 3-D scaffolds. Crosslinking via photopolymerisation provides many benefits, including rapid polymerisation times under physiological conditions. At present, most synthetic polymers used in tissue engineering are linear structure, however, they suffer from poor solution properties, non-homogenous crosslinking properties and limited control of polymer modification. Dendritic polymers have unique properties, such as good solubility, low viscosity and high functionality, due to their 3-D architecture. Grinstaff synthesised a photocrosslinkable dendrimer for corneal wound healing sealant and cartilage repair. However, dendrimers have to be prepared by solvent-intensive and multi-step synthetic routes, most importantly, it is difficult to tailor the composition and structure of dendrimers for a wide range of special applications. By contrast, hyperbranched polymers, less controlled dendritic polymer architectures, can be synthesised more easily by a single-step reaction via a range of synthetic strategies. Could the use of such hyperbranched polymers overcome the synthetic barrier of dendrimers? The limitation of current synthetic strategies for hyperbranched polymers are either the need of special monomers (ABn or AB* inimer), and/or, only poor controlled structure and low degree of branching polymers can be obtained. Therefore, up till now, such materials are difficult to be considered in medical applications. I have recognised that a breakthrough in synthesis of hyperbranched materials with controlled chain structure and high degree of branching using more accessible monomers could facilitate a completely new approach to their biological and biomedical applications.Recently, the Nottingham team has developed a deactivation enhanced ATRP method, which opens up the field significantly and allows simple use of readily available and inexpensive multifunctional vinyl monomers to synthesise hyperbranched polymers with high degree of branching, controlled molecular weight and chain structure. Such hyperbranched polymer materials could be extremely important for biological and biomedical applications. Furthermore, the products carry a multitude of reactive functionalities (e.g. double bonds and halogen functional groups) that can be post-functionalised and modified for specific applications by end capping with short chains, organic molecules and terminal grafting. By these modifications, the material properties, such as functionality, polarity, solubility and flexibility of the hyperbranched polymers, can be conveniently tailored to meet the application requirements. The polyvinyl functional groups can be used as corsslinking sites by photo stimuli to form 3-D structure. My aim is to design and synthesise a broad spectrum of tailored, novel hyperbranched polymers for biological and biomedical applications using the recently developed facile synthetic strategy, deactivation enhanced ATRP. This proposal targets the development of novel photocrosslinkable hyperbranched polymers as injectable scaffold materials for cartilage tissue repair. The hydrogels from the targeted hyperbranched polymers will achieve better biological response with tailored mechanical properties, integrin-mediated cell adhesion and control of growth factor release. The research will include three tasks with some subtasks as detailed in the Case of Support.

Publications


10 25 50
Omer R (2015) Hydrogels from dextran and soybean oil by UV photo-polymerization in Journal of Applied Polymer Science
Tai H (2012) pH-Responsive Hyperbranched Copolymers from One-Pot RAFT Copolymerization in Macromolecular Materials and Engineering

Related Projects

Project Reference Relationship Related To Start End Award Value
EP/E042619/1 01/09/2007 28/02/2009 £256,144
EP/E042619/2 Transfer EP/E042619/1 01/03/2009 28/02/2011 £134,250
 
Description In tissue engineering, injectable scaffolds offer the possibility of homogeneously distributing cells and molecular signals throughout the scaffold, and can be injected directly into cavities with irregular shapes and sizes. The use of injectable scaffolds can also minimise patient discomfort, risk of infection, scar formation, and the cost of treatment. The ultimate goal of my fellowship is to develop injectable scaffolds for tissue repair and wound healing. One of the challenging issues for the development of injectable scaffolds is to find suitable materials which can solidify in-situ to form 3-D scaffolds. Smart polymers which change in response to external stimuli such as temperature, pH and light have attracted much attention in terms of such applications. The objective of my proposed research project for this three-year EPSRC postdoctoral fellowship is to develop smart hyperbranched photocrosslinkable multifunctional biomaterials with tailored mechanical properties and functionalities for cell adhesion of specific cell types via decorating with peptide motifs as well as for controlled release of therapeutic protein drug/growth factors. These fine design and control will lead to novel injectable systems with a significant advance over current hydrogel systems.

The proposed research project includes three main tasks with two stages. The first stage is to develop novel PEG based biocompatible and photocorsslinkable hyperbranched polymer systems using commercially available monomers. The research subtasks include monomer selection, synthesis and characterization of hyperbranched polymers as well as gel formation studies and evaluations on mechanical and biological properties of the gels. The methodologies established on polymer synthesis, characterization and property evaluations during the first stage are further used and developed in the second stage of the project on the development of biodegradable hyperbranched polymers using non-commercially available biodegradable branching agent (i.e. macromers) aiming to introduce biodegradable fragments into the targeted hyperbranched polymers.

I have successfully developed thermal responsive and photocrosslinkable PEGMEMA-PPGMA-EGDMA hyperbranched polymers with potential applications for injectable scaffolds via deactivation enhanced atom transfer radical polymerisation (ATRP) and reversible addition-fragmentation chain transfer polymerisation (RAFT). I have also developed pH responsive poly (PAA-PEGDA) hyperbranched polymers with potential applications for drug delivery via RAFT.

Thermoresponsive PEGMEMA-PPGMA-EGDMA hyperbranched copolymers developed have demonstrated the lower critical solution temperatures (LCST) ranging from 20 to 44 oC and with high levels of branching (30-50 mol %) and vinyl functionality (5-25 mol %). The photocrosslinking property of the materials has been investigated using UV lights and UV curing cell system attached to the Rheometer. I have successfully secured an award of the Partnership Programme in Science Research Visits fund from the British Council and Platform Bèta Techniek, which supported me to build up the collaborations with the Department of Pharmaceutics at Utrecht University in Netherlands and conduct real time photocrosslinking studies. Cytotoxicity assessments (Live/Dead staining and the Alamar Blue assay) for these hyperbranched copolymers using mouse C2C12 myoblast cell line and 3T3 fibroblast cell line confirmed their cytocompatibility in vitro. The studies have illustrated that hyperbranched copolymers PEGMEMA-PPGMA-EGDMA have great capacity to be developed for use as smart injectable materials in Regenerative Medicine such as wound healing and tissue repair. Further structure modifications, by introducing cell adhesion peptide moieties was investigated for the assessment on their ability to improve cell adhesion to these polymer gels.

The design, preparation and evaluations of biodegradable injectable hyperbranched systems using the methodologies established are the second stage of the research project. A range of macromers with different lengths of lactoyl segments have been successfully prepared. The hyperbranched biodegradable copolymers have also been achieved using these macromers as branching agent through co-polymerisation with PEGMEMA (Polyethylene Glycol Methyl Ether Methacrylate) via RAFT. Biodegradable hyperbranched polymers developed are further used to fabricate biodegrable hyrogels, which are characterised on their mechanical, swelling, release and biological properties using the methodologies established during the first stage of the project, i.e. the development of PEG based non-biodegradable hydrogels.

pH-responsive polyanionic polymers have attracted much attention in regenerative medicine and tissue engineering as carriers or matrix to facilitate intracellular and extracellular therapeutic drug delivery and release. Among them, synthetic poly(propylacrylic acid) (PPAA) and its derivatives (linear copolymers and engineered bioconjugates) have demonstrated great potential for intracellular delivery of a variety of therapeutics, such as DNA, RNA, peptides and proteins because they demonstrate effective endosomal membrane disruptive activity due to the change in hydrophobic and hydrophilic properties at the physiologically relevant pHs between 5.0 and 7.4. In recent years, along with the development of modular dendrimers, the multivalence and ease synthesis of dendrtic/hyperbranched polymers have made them as attractive candidates for biological and biomedical applications. These polymers closely parallel biological macromolecules in size while their multifunctional groups make them to retain high solubility with high drug load, and in the mean time allows multiplicity of chemical content for drug conjugating and cell targeting, interaction and imaging. It is hypothesized that propylacrylic acid-containing dendritic/hyperbranched polymers could have advanced properties over their linear counterparts because their unique 3-D architecture will allow them to be decorated with multifunctional therapeutic, diagnostic and imaging moieties. I worked at the Department of Bioengineering at the University of Washington (Seattle) with Prof Allan Hoffman and Prof Patrick Stayton on the development of pH-sensitive dendritic polyanion copolymer which demonstrated enhanced membrane disruptive activity and the ability to complex with cationic protein. It is anticipated that poly(PAA-PEGDA) dendritic copolymers have potential to be used in polycation complexes (polyplexes or lipoplexes) formulations to enhance intracellular delivery of therapeutics. In addition, because of their dendritic architectures with multifunctionalties of RAFT agent moieties, acrylate and carboxylic acid, these dendritic copolymers can be used as building blocks to covalently conjugate with other functional therapeutic or/and diagnostic (macro)molecules; or as macro-chain transfer agents (marco-CTA) to form core-shell structures for a varity of specific applications.

In summary, the thermal-responsive, photocrosslinkable and biodegadable PEG based hyperbranched polymers have been succesfully designed and prepared with potential applications for injectable scaffolds via ATRP and RAFT. Furthermore, I have also developed pH responsive poly (PAA-PEGDA) hyperbranched polymers with potential applications for drug delivery via reversible addition-fragmentation chain transfer polymerisation (RAFT). So far, 16 peer reviewed research journal papers have been published from this EPSRC project. I have also presented my research findings at national and international conferences.
Exploitation Route The novel hyperbranched polymers developed with thermo- or pH responsive properties can be used for drug delivery and tissue engineering applications. The facile synthetic methods developed can also be used for the preparation of other types of smart and crosslinkable biopolymers.
Sectors Chemicals,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology
 
Description The novel crosslinkable hyperbranched polymers synthesized via living/controlled polymerisations with thermo- or pH responsive properties have demonstrated great potentials to be used for deliver drug and tissue engineering applications. The facile synthetic methods can also be used for the preparation of other types of smart and crosslinkable biopolymers.
First Year Of Impact 2013
Sector Chemicals,Healthcare,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology
Impact Types Cultural,Economic
 
Description Interreg Scheme
Amount € 651,000 (EUR)
Funding ID 059 
Organisation European Commission (EC) 
Department European Regional Development Fund (ERDF)
Sector Public
Country European Union (EU)
Start 02/2012 
End 07/2014
 
Description KESS II
Amount £61,000 (GBP)
Organisation European Commission (EC) 
Department European Social Fund
Sector Public
Country European Union (EU)
Start 09/2016 
End 08/2019
 
Description Knowledge Economy Skills Scholarship (KESS)
Amount £69,000 (GBP)
Organisation European Commission (EC) 
Department European Social Fund
Sector Public
Country European Union (EU)
Start 10/2016 
End 09/2019
 
Description Life + "Environment Policy and Governance"
Amount € 110,000 (EUR)
Organisation University of Wales 
Sector Academic/University
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 09/2012 
End 08/2014
 
Description Life Science Research Network Wales
Amount £73,000 (GBP)
Organisation National Research Network, Life Sciences and Health 
Sector Public
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 10/2017 
End 09/2019
 
Description Mobility Scholarship
Amount £800 (GBP)
Organisation Santander Bank 
Sector Private
Country United States of America
Start 07/2014 
End 08/2014
 
Description ConVaTec 
Organisation ConvaTec
Country United States of America 
Sector Private 
PI Contribution We succeeded in applying for the KESS II PhD studentship in Jan 2016. The PhD student will work on a project to develop biopolymers for wound healing products from Sept 2016.
Collaborator Contribution We succeeded in applying for the KESS II PhD studentship in Jan 2016. The PhD student will work on a project to develop biopolymers for wound healing products from Sept 2016.
Impact Not yet
Start Year 2016
 
Description Ireland 
Organisation National University of Ireland, Galway (NUI)
Country Ireland, Republic of 
Sector Academic/University 
PI Contribution Dr Wenxin Wang's research team and my research team have good collaborations during the past few years. Our collaboration has been close and active because our groups/departments have complementary skills/facilities that we can share. Dr Wang's group located at NUI Galway from 2008-2013 and Dr Wang relocated his group to UCD in Nov 2013. The strength of my group lies in organic and polymer synthesis and the School of Chemistry at Bangor University has well equipped synthetic labs with a range of modern chemical analysis facilities. To prepare functionalized biomacromolecules for drug delivery and tissue engineering, functional monomers and other chain transfer agents are required. My group prepares these functional compounds/polymers in our lab and provide these to my partners for further formulation and in-vitro and in-vivo bio-evaluations.
Collaborator Contribution Dr Wang's lab is well equipped with modern cell-culture and bio-assay facilities. Myself and my team members have benefited greatly by working in Dr Wang's lab and have had good interactions with his group members.
Impact This collaboration is multi-disciplinary between chemistry, material science and life science. We have produced several joint publications (see below): 1. Zhao, T.; Zhang, H.; Zhou, D.; Gao, Y.; Dong, Y.; Greiser, U.; Tai, H.; Wang, W.. 'Water Soluble Hyperbranched Polymers from Controlled Radical Homopolymerization of PEG Diacrylate', RSC ADVANCES, 2015, 5, 33823-33830. 2. Omer, R. A.; Hughes, A.; Hama J. R. ; Wang, W. and Tai, H. (Corresponding Author) Hydrogels from Dextran and Soybean Oil by UV Photopolymerisation, JOURNAL OF APPLIED POLYMER SCIENCE, 2014, 132, 41446 3. Kennedy, R.; Hassan W. U.; Tochwin, A.; Zhao, T.; Dong, Y.; Wang, Q.; Tai, H. (Corresponding Author) and Wang, W. In situ formed hybrid hydrogels from PEG based multifunctional hyperbranched copolymers: A RAFT approach, POLYMER CHMEMISTRY 2014, 5, 1838-1842. 4. Tai, H. (Corresponding Author); Tochwin, A.; Wang, W. Thermoresponsive hyperbranched polymers via in-situ RAFT copolymerisation of PEG based monomethacrylate and dimethacrylate monomers, JOURNAL OF POLYMER SCIENCE, PART A, POLYMER CHEMISTRY, 2013, 51 (17) 3751-3761. 5. Tai, H. (Corresponding Author); Duvall,C.L.; Hoffman, A.S.; Stayton, P.S.; Wang, W. pH-Responsive hyperbranched copolymers from one-pot reversible addition-fragmentation chain transfer copolymerization, MACROMOLECULAR MATERIALS ?INEERING, 2012, 297, 1175-1183. 6. Zheng, Y.; Newland,B.; Tai, H. (Corresponding Author) ; Pandit, A.; and Wang, W. Single cyclized molecule structure from RAFT homopolymerization of multi-vinyl monomers, CHEMICAL COMMUNICATIONS, 2012, 48 (25), 3085 - 3087 7. Aied, A.; Glynn, B.; Cao, H.; Zheng, Y.; Tai, H. (Corresponding Author); Pandit, A.; Wang, W.; A Fluorescently labeled, hyperbranched polymer synthesized from DE-ATRP for the detection of DNA hybridization, POLYMER CHEMISTRY, 2012, 3,332-334. 8. Dong, Y.; Hassan, W.; Zheng, Y.; Saeed, A.O.; Cao, H.; Tai, H. (Corresponding Author); Pandit, A.; and Wang, W. Thermoresponsive hyperbranched copolymer with multi acrylate functionality for in situ cross-linkable hyaluronic acid composite semi-IPN hydrogel, JOURNAL OF MATERIALS SCIENCE: MATERIALS IN MEDICINE, 2012, 23, 25-35. 9. Dong,Y.; Saeed, A.O.; Hassan, W.; Tai, H. (Corresponding Author); Pandit, A.; and Wang, W. One-step preparation of thiol-ene clickable PEG based thermoresponsive hyperbranched copolymer for in situ crosslinking hybrid hydrogel, MACRPMOL. RAPID COMMUN, 2012, 22(2),120-126. 10. Dong, Y.; Cao, H.; Mathew, A.; Newland, B. E.; Saeed, A.O.; Gunning, P.; Magnusson, J.P.; Alexander, C.; Tai, H. (Corresponding Author); Pandit, A.; Wang, W. Dual stimuli responsive PEG based dendritic polymers, POLYMER CHEMISTRY, 2010, 1, 827-830. 11. Newland, B. E.; Tai, H.; Zheng, Y.; Velascoa, D. B.; Howdle, S. M.; Alexander, C.; Wang, W.; Pandit, A.; A highly effective gene delivery vector - dendritic poly(2-(dimethylamino) ethyl methacrylate) from in-situ deactivation enhanced ATRP, CHEMICAL COMMUNICATIONS, 2010, 46, 4698 - 4700. 12. Tai, H. (Corresponding Author); Howard, D.; Takae, S.; Wang, W.; Vermonden, T.; Hennink, W. E.; Stayton P.S.; Hoffman, A.S.; Endruweit, A.; Alexander, C.; Howdle, S.M.; Shakesheff, K.M. Photocrosslinked hydrogels from thermoresponsive PEGMEMA-PPGMA-EGDMA copolymers containing multiple methacrylate groups: mechanical property, swelling, protein release and cytotoxicity, BIOMACROMOLECULES, 2009, 10(10), 2895-2903. 13. Tai, H. (Corresponding Author); Wang, W.; Vermonden, T., Heath, F.; Hennink, W. E., Alexander, C.; Shakesheff, K. M. and Howdle, S. M., Thermoresponsive and photocrosslinkable PEGMEMA-PPGMA-EGDMA copolymers from one-step ATRP synthesis, BIOMACROMOLECULES, 2009, 10 (4), 822-828. 14. Tai, H. (Corresponding Author); Wang, W.; Alexander, C.; Shakesheff, K. M.; Howdle, S. M., Thermal-responsive and photocrosslinkable hyperbranched polymers synthesised by deactivation enhanced ATRP and RAFT polymerisations, JOURNAL OF CONTROLLED RELEASE, 132, 3, e48-e50, 2008 (Proceedings of the Tenth European Symposium on Controlled Drug Delivery, Noordwijk aan Zee, The Netherlands, 02-04 April 2008).
Start Year 2008
 
Description Ireland 
Organisation University College Dublin (UCD)
Country Ireland, Republic of 
Sector Academic/University 
PI Contribution Dr Wenxin Wang's research team and my research team have good collaborations during the past few years. Our collaboration has been close and active because our groups/departments have complementary skills/facilities that we can share. Dr Wang's group located at NUI Galway from 2008-2013 and Dr Wang relocated his group to UCD in Nov 2013. The strength of my group lies in organic and polymer synthesis and the School of Chemistry at Bangor University has well equipped synthetic labs with a range of modern chemical analysis facilities. To prepare functionalized biomacromolecules for drug delivery and tissue engineering, functional monomers and other chain transfer agents are required. My group prepares these functional compounds/polymers in our lab and provide these to my partners for further formulation and in-vitro and in-vivo bio-evaluations.
Collaborator Contribution Dr Wang's lab is well equipped with modern cell-culture and bio-assay facilities. Myself and my team members have benefited greatly by working in Dr Wang's lab and have had good interactions with his group members.
Impact This collaboration is multi-disciplinary between chemistry, material science and life science. We have produced several joint publications (see below): 1. Zhao, T.; Zhang, H.; Zhou, D.; Gao, Y.; Dong, Y.; Greiser, U.; Tai, H.; Wang, W.. 'Water Soluble Hyperbranched Polymers from Controlled Radical Homopolymerization of PEG Diacrylate', RSC ADVANCES, 2015, 5, 33823-33830. 2. Omer, R. A.; Hughes, A.; Hama J. R. ; Wang, W. and Tai, H. (Corresponding Author) Hydrogels from Dextran and Soybean Oil by UV Photopolymerisation, JOURNAL OF APPLIED POLYMER SCIENCE, 2014, 132, 41446 3. Kennedy, R.; Hassan W. U.; Tochwin, A.; Zhao, T.; Dong, Y.; Wang, Q.; Tai, H. (Corresponding Author) and Wang, W. In situ formed hybrid hydrogels from PEG based multifunctional hyperbranched copolymers: A RAFT approach, POLYMER CHMEMISTRY 2014, 5, 1838-1842. 4. Tai, H. (Corresponding Author); Tochwin, A.; Wang, W. Thermoresponsive hyperbranched polymers via in-situ RAFT copolymerisation of PEG based monomethacrylate and dimethacrylate monomers, JOURNAL OF POLYMER SCIENCE, PART A, POLYMER CHEMISTRY, 2013, 51 (17) 3751-3761. 5. Tai, H. (Corresponding Author); Duvall,C.L.; Hoffman, A.S.; Stayton, P.S.; Wang, W. pH-Responsive hyperbranched copolymers from one-pot reversible addition-fragmentation chain transfer copolymerization, MACROMOLECULAR MATERIALS ?INEERING, 2012, 297, 1175-1183. 6. Zheng, Y.; Newland,B.; Tai, H. (Corresponding Author) ; Pandit, A.; and Wang, W. Single cyclized molecule structure from RAFT homopolymerization of multi-vinyl monomers, CHEMICAL COMMUNICATIONS, 2012, 48 (25), 3085 - 3087 7. Aied, A.; Glynn, B.; Cao, H.; Zheng, Y.; Tai, H. (Corresponding Author); Pandit, A.; Wang, W.; A Fluorescently labeled, hyperbranched polymer synthesized from DE-ATRP for the detection of DNA hybridization, POLYMER CHEMISTRY, 2012, 3,332-334. 8. Dong, Y.; Hassan, W.; Zheng, Y.; Saeed, A.O.; Cao, H.; Tai, H. (Corresponding Author); Pandit, A.; and Wang, W. Thermoresponsive hyperbranched copolymer with multi acrylate functionality for in situ cross-linkable hyaluronic acid composite semi-IPN hydrogel, JOURNAL OF MATERIALS SCIENCE: MATERIALS IN MEDICINE, 2012, 23, 25-35. 9. Dong,Y.; Saeed, A.O.; Hassan, W.; Tai, H. (Corresponding Author); Pandit, A.; and Wang, W. One-step preparation of thiol-ene clickable PEG based thermoresponsive hyperbranched copolymer for in situ crosslinking hybrid hydrogel, MACRPMOL. RAPID COMMUN, 2012, 22(2),120-126. 10. Dong, Y.; Cao, H.; Mathew, A.; Newland, B. E.; Saeed, A.O.; Gunning, P.; Magnusson, J.P.; Alexander, C.; Tai, H. (Corresponding Author); Pandit, A.; Wang, W. Dual stimuli responsive PEG based dendritic polymers, POLYMER CHEMISTRY, 2010, 1, 827-830. 11. Newland, B. E.; Tai, H.; Zheng, Y.; Velascoa, D. B.; Howdle, S. M.; Alexander, C.; Wang, W.; Pandit, A.; A highly effective gene delivery vector - dendritic poly(2-(dimethylamino) ethyl methacrylate) from in-situ deactivation enhanced ATRP, CHEMICAL COMMUNICATIONS, 2010, 46, 4698 - 4700. 12. Tai, H. (Corresponding Author); Howard, D.; Takae, S.; Wang, W.; Vermonden, T.; Hennink, W. E.; Stayton P.S.; Hoffman, A.S.; Endruweit, A.; Alexander, C.; Howdle, S.M.; Shakesheff, K.M. Photocrosslinked hydrogels from thermoresponsive PEGMEMA-PPGMA-EGDMA copolymers containing multiple methacrylate groups: mechanical property, swelling, protein release and cytotoxicity, BIOMACROMOLECULES, 2009, 10(10), 2895-2903. 13. Tai, H. (Corresponding Author); Wang, W.; Vermonden, T., Heath, F.; Hennink, W. E., Alexander, C.; Shakesheff, K. M. and Howdle, S. M., Thermoresponsive and photocrosslinkable PEGMEMA-PPGMA-EGDMA copolymers from one-step ATRP synthesis, BIOMACROMOLECULES, 2009, 10 (4), 822-828. 14. Tai, H. (Corresponding Author); Wang, W.; Alexander, C.; Shakesheff, K. M.; Howdle, S. M., Thermal-responsive and photocrosslinkable hyperbranched polymers synthesised by deactivation enhanced ATRP and RAFT polymerisations, JOURNAL OF CONTROLLED RELEASE, 132, 3, e48-e50, 2008 (Proceedings of the Tenth European Symposium on Controlled Drug Delivery, Noordwijk aan Zee, The Netherlands, 02-04 April 2008).
Start Year 2008
 
Description Netherland 
Organisation Utrecht University
Country Netherlands, Kingdom of the 
Sector Academic/University 
PI Contribution I had a fantastic one-week research visit in July 2008 at Utrecht University and carried out real-time rheological studies on my thermoresposive and photocrosslinkabe materials. This research visit was partially funded by British Council which has created the great opportunity for me to establish collaborations with Prof Wim Hennink in Utrecht University. We have two joint publications on this collaboration work.
Collaborator Contribution Utrecht University hosted my one-week research visit. I have conducted real-time rheological studies there using their facilities.
Impact Two joint publications: 1. Tai, H. (Corresponding Author); Howard, D.; Takae, S.; Wang, W.; Vermonden, T.; Hennink, W. E.; Stayton P.S.; Hoffman, A.S.; Endruweit, A.; Alexander, C.; Howdle, S.M.; Shakesheff, K.M. Photocrosslinked hydrogels from thermoresponsive PEGMEMA-PPGMA-EGDMA copolymers containing multiple methacrylate groups: mechanical property, swelling, protein release and cytotoxicity, BIOMACROMOLECULES, 2009, 10(10), 2895-2903. 2. Tai, H. (Corresponding Author); Wang, W.; Vermonden, T., Heath, F.; Hennink, W. E., Alexander, C.; Shakesheff, K. M. and Howdle, S. M., Thermoresponsive and photocrosslinkable PEGMEMA-PPGMA-EGDMA copolymers from one-step ATRP synthesis, BIOMACROMOLECULES, 2009, 10 (4), 822-828.
Start Year 2008
 
Description School of Medical Sciences, BU 
Organisation Bangor University
Department Institute of Medical and Social Care Research (IMSCAR)
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Academic/University 
PI Contribution This is an internal collaboration between the School of Chemistry (my team) and School of Medicine (my collaborators) in Bangor University. This partnership is very important, because my research is multidisciplinary to develop biopolymers for biomedical applications, which requires me to have good interaction and collaborations with biologist and clinicians.
Collaborator Contribution This is an internal collaboration between the School of Chemistry (my team) and School of Medicine (my collaborators) in Bangor University. This partnership is very important, because my research is multidisciplinary to develop biopolymers for biomedical applications, which requires me to have good interaction and collaborations with biologist and clinicians.
Impact We are working jointly on a KESS II PhD studentship project from 2016.
Start Year 2015
 
Description UW 
Organisation University of Washington
Country United States of America 
Sector Academic/University 
PI Contribution I won the Life Science Interface (LSI) Research Fellowship from EPSRC in 2007, which supported me as an independent Principal Investigator working on the development of functional dendritic polymers as injectable systems for tissue engineering and drug delivery applications. I have successfully developed photo-crosslinkable and thermo-responsive dendritic polymers which have demonstrated great potentials to be used as tissue engineering scaffolds. From Aug 2008 to Feb 2009, I worked in Bioengineering Department at the University of Washington in Seattle, USA as a visiting scholar to further extend and build up my research profile in the field of smart polymers for targeted drug delivery. During this period, I developed a pH-sensitive dendritic polyanion which demonstrated membrane disruptive properties and had potential to be used for intracellular delivery of therapeutic drugs.
Collaborator Contribution The mentors at UW (Prof Hoffman and Prof Stayton) had regular scientific discussions with me when I worked at UW. This collaboration has been maintained after I left UW. Two joint papers have been published.
Impact 1. Tai, H. (Corresponding Author); Duvall,C.L.; Hoffman, A.S.; Stayton, P.S.; Wang, W. pH-Responsive hyperbranched copolymers from one-pot reversible addition-fragmentation chain transfer copolymerization, MACROMOLECULAR MATERIALS ?INEERING, 2012, 297, 1175-1183. 2. Tai, H. (Corresponding Author); Howard, D.; Takae, S.; Wang, W.; Vermonden, T.; Hennink, W. E.; Stayton P.S.; Hoffman, A.S.; Endruweit, A.; Alexander, C.; Howdle, S.M.; Shakesheff, K.M. Photocrosslinked hydrogels from thermoresponsive PEGMEMA-PPGMA-EGDMA copolymers containing multiple methacrylate groups: mechanical property, swelling, protein release and cytotoxicity, BIOMACROMOLECULES, 2009, 10(10), 2895-2903
Start Year 2008
 
Description Biodegradable Polymers for Tissue Engineering and Drug Delivery 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Discussions.

Discussions have stimulated new ideas. Potential collaborations were sought.
Year(s) Of Engagement Activity 2011
 
Description Dendritic functional polymers: synthesis, properties and applications 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Local
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Discussions were held.

Potential collaborations were sought.
Year(s) Of Engagement Activity 2009
 
Description Functional Polymers: Design, Synthesis, Characterisation and Applications 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Training and discussions at Revolutionary Polymer Solutions (Revolymer), Deeside, Flintshire, United Kingdom.

After the talk, the company has expressed their interest in developing collaborations.
Year(s) Of Engagement Activity 2012
 
Description Mimicking nature leads to discoveries 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact News paper article a Western Mail.

Not seen obvious impacts yet. However, this article has increased the visibility of my research profile.
Year(s) Of Engagement Activity 2012
 
Description University Open Days and UCAS Open Days 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? Yes
Geographic Reach Local
Primary Audience Schools
Results and Impact More students have been attracted to study chemistry courses.
Year(s) Of Engagement Activity 2007,2008,2009,2010,2011