MIP 2014 Conference Report

The 8th International Conference on Molecular Imprinting was held on September 18-21, 2014 in Zhenjiang, China, under the auspices of Jiangsu University. Chairman of the conference was Songjun Li, President of the Chinese Advanced Materials Socitey. This first Asian meeting in the field attracted ca 300 delegates predominantly from the academic sector. The contributions covered a wide range of subjects and applications the latter mainly dealing with various aspects related to life and analytical sciences. The broad scope confirms the versatility of the simple concept of imparting molecular memory into a polymer and its relevance in very different technology contexts.

Figure. 1 The MIP 2014 conference hotel

Day 1

The first morning plenary lecture was given by Klaus Mosbach (Lund University, Sweden), one of the pioneers in the field. In his lecture he looked back on the early developments in the field discussing his own work on enzyme immobilization and affinity chromatography and its influence on the early developments in the field. The talk ended with a philosophical outlook addressing the poor industrial participation and possible reasons for the lack of tangible commercial progress.

The second plenary speaker was Yukui Zhang (Dalian Institute of Chemical Physics, China) who discussed various forms of protein imprinted materials for affinity applications in proteomics research. Significant progress was reported using the epitope imprinting concept, typically employing peptides corresponding to solvent accessible terminal sequences as templates for generating protein recognitive particles.  This approach seems to gain ground as indicated by other talks during the symposium (I-066, I-052).   The third plenary talk was given by Karsten Haupt (Universite de Technologie de Compiegne, FR) who gave valuable insights into the factors influencing the recognitive properties of MIP nanoparticles and ways to improve them. Several interesting approaches for producing protein sized MIP particles and novel architectures were presented, comprising the use of dendritic multi-iniferters, immobilized templates or anchoring monomers and the coating of MIP films on various cores, the latter adapted for applications in sensing or cell imaging. The use of MIPs as contrast agents in cell imaging was also a recurring subject during the conference featured in talks by Meiping Zhao (I-006) and Börje Sellergren (PL-007).

The afternoon session A of day one opened with a key note lecture by Ian Nicholls (Linnaeus University, Sweden) outlining novel approaches to hierarchical polymer architectures for mainly sensing applications. Using biotin as a model template, imprinting using both soft (liquid crystals) and hard (latex particles) templating was described and critically compared and several interesting results were presented.

This was followed by contributed lectures covering electrochemical sensors (I-002, I-072), molecular modeling of MIP formation (I-004) and heavy metal ion-imprinting for environmental analysis (I-005). Electrochemical sensors was also a recurring subject during the conference, notably in the talks by Wlodzimierz Kutner (I-032, Warsaw, Poland) and Jinaping Li (I-046, Guilin Uinversity, China).

The second keynote lecture of this session was given by Meiping Zhao (Peking University). This speaker outlined a rational approach to the synthesis of multifunctional biologically active enzyme inhibiting nanoparticles. Employing RAFT chemistry, nuclease imprinted shell/magnetic core particles were synthesised and optimized for magnetic field mediated transfer into cell nucleus. Interestingly, both selective inhibition and cell internalization could be demonstrated using fluorescently trackable particles.

The remaining talks during this session covered the well proven application of MIPs as solid phase extraction sorbents for sensitive analysis (I-061, I-007, I-009). This application was also the subject of numerous other talks of the conference.

Session B opened with a talk given by Lei Ye (Lund University, Sweden) which described various approaches to produce multifunctional MIP nanoparticles. The versatility of the click reaction for joining complementary functionalized nanoparticles was highlighted. Chemistries for derivatizing RAFT containing particles was also described.

The use of controlled radical polymerization, notably RAFT chemistry, was also the subject of a later key note talk by Huiqi Zhang (I-076, Nankai University).  His technique of controlled radical precipitation polymerization allows for controlled synthesis of hydrophilic MIPs, of controlled size and low polydispersity, compatible with a variety of biological and food matrices.

Following talks in this session covered heavy metal removal (I-012), electropolymerized MIPs (I-014) and sensors (I-015 and I-063).

The second afternoon session B opened with a keynote lecture given by Junqiu Liu (Jilin University, China) on MIP based enzyme mimics. Recent work on artificial selenoenzymes was described in the talk.

Among the following contributed talks a procedure for generating non-thiol based Au-C surface grafted MIP films on gold nanorods can be mentioned. This could offer a straightforward way to produce gold-MIP nanocomposites (I-019). Finally a demonstration of an electrochemical or heat transfer sensor for sensitive measurements of neurotransmitters or nicotine in body fluids (I-020) was reported.

Day 2

During day 2, session A opened with a key note talk by Elena Piletska (University of Leicester, UK) on new formats for molecularly imprinted polymers providing a critical discussion on their relative merits and limitations.

Gilke de Middeleer (Ghent University, NL) adressed the well known need for rapid and simple testing methods for mycotoxins in food. The solution proposed was a platform for multiplex mycotoxin analysis comprising a porous scaffold with regular structure capable of harboring geometrically addressable MIP nanoparticles.  A similar approach was later described by Maria Moreno Bondi (I-034, University of Madrid, Spain) and in the later key-note presentation by Guillermo Orellana (I-051, University of Madrid, Spain) for the preparation of arrays with optically addressable nanoparticles complementary to fluoroquinolone antimicrobials.

The second morning keynote in Session A was delivered by Songjun Li (Jiangsu University, China) who addressed challenges in the development of MIP based catalysts, notably those that are designed to feature thermo-switchable properties.The talk was followed by contributions comprising topics like vesicular imprinting (I-027) and MIP-pills (I-028).

The Session B morning session featured David Spivak (Lousiana State University, US) as key-note lecturer. He reported on a highly sensitive diffraction grating sensor for virus detection relying on virusimprinted aptamer hydrogels. Impressive sensitivity enhancements were achieved by employing two complementary aptamers targeting the virus surface.

Figure. 2 David Spivak, chairman of MIP2010, enjoying the view over Zhenjiang.

This talk was followed by Wlodzimierz Kutner (I-032, Warsaw University, Poland) who reported on rational approaches for imprinting in conducting polymer scaffolds and how to combine the polymers with various sensor transducers. This simple approach to generate imprinted films is growing in popularity as indicated by other contributions during the conference.

Three talks followed focusing on synthetic chemistry. Two of the talks covered host guest chemistry and synthetic approaches to improve the binding of small molecules to MIP receptors. Hence, Yuejin Tong (I-033, Fuijan University, China) reported on a sacrifical spacer approach to the recognition of diphenylethers while Andrew Hall (I-035, Medway University, UK) described a generic dummy template approach for imprinting carbohydrate containing targets. Paolo Bonomi (I-069, University of Compiegne, FR) delivered a talk on water soluble iniferters for producing nanomaterials for biological applications.

Romana Schirhagl (Stanford University, US) finally concluded the morning session with a talk on MIPs for cell chromatography.  Bacteria recognitive surfaces produced by a stamping process could be used to selectively separate bacteria when placed in a microfluidic channel. The separation efficiency depended on the cell orientation which was subsequently exploited by producing anisotropic imprints oriented along the direction of the flow path.

The afternoon session A featured a key note lecture by Kal Karim (Leicester University, UK) providing an overview of the use of molecular modelling in MIP design, a now widespread and increasingly powerful tool for predicting and understanding polymer performance.

Several talks were devoted to MIPs and NIPs for omics applications. Apart from those already discussed relying on traditional protein or epitope imprinting many talks addressed the need for alternative affinity techniques in targeted proteomics i.e. to enrich posttranslationally modified (PTM) proteins.  The talks by Jing Chen (Ruhr University Bochum) and Feng Shen (China Agricultural University) addressed the need for improved enrichment techniques in phosphoproteomics.  In the talk by Jing Chen, a robust and effective method for side chain selective phosphopeptide enrichment was described. This allowed the identification of a large number of unique phosphopeptides and the discovery of novel previously unknown sites of phosphorylation from extremely small sample sizes.  The aspect of MIP based biodiscovery was later emphasised in the final plenary talk by Börje Sellergren (Malmö University) where MIPs targetting different PTMs and bioactive lipids were described. The latter subject had been previously described in more detail in the talk by Federico Torta (National University of Singapore).

Alessandra Bossi (University of Verona) reported a simple approach to targeted proteomics relying on peptide imprinted polymers capturing proteotypic peptides prior to MALDI mass spectrometry. The approach was demonstrated for three peptides typic for one protein, troponine I.  Applying the three corresponding MIPs on the MALDI target post enrichment from digested spiked serum samples led to signficant enhancements of the signals corresponding to the three proteotypic peptides.

In a key note presentation by Zhen Liu (Nanjing University, China) a versatile platform for the recognition and sensing of glycoproteins was reported. This addresses a field in strong need of improved recognition chemistry. Highly sensitive ELISA like assays was reported and in particular those bypassing the need for both detection antibodies and enzymes should be noted.

Figure. 3 David Spivak and Börje Sellergren.

Day 3

Due to the unfortunate health related absence of the SMI president, Michael Whitcombe, the final plenary session contained only three talks. The session was opened by Kenneth J. Shea who described a new paradigm in molecular recognition somewhat reminiscent of the immunoresponse. This is based on the notion that loosely crosslinked "adaptable" high polymers exceeding a certain number of repeat units and monomers exhibit sufficient diversity for specific polymer chains showing affinity for a guest molecule, e.g. a protein, to exist.  This concept was demonstrated by showing a number of independent examples addressing protein capture, protein depletion and diagnostics or therapeutic applications e.g. inhibition of cell surface interactions.

This lecture was then followed by an equally fascinating talk by Sergey Piletsky (University of Leicester, UK) describing MIP nanoparticles synthesised by a generic solid state synthesis protocol. The versatiliy of this approach was shown by a number of examples using particles as capture phases in ELISA assays, in imaging, in sensors or for therapeutic applications, some of the latter very similar to those addressed in the preceeding talk.  It remains to be seen how these two approaches to generate recognitive particles compare with each other.

The poster session included 31 posters with 13 posters covering applications in the areas of food analysis (3), environmental technologies (5) and pharmaceutical analysis (5). 7 posters covered methodological and fundamental aspects of MIP synthesis and characterization whereas the remaining posters covered omics sciences, protein recognition, therapeutics and catalysis in roughly equal proportions.

 The conference ended with a tour in the city Zhenjiang and a pleasant walk along the Yangtsee river.

Figure. 4 Stroll along the Yangtsee river.

Malmö, October 8, 2015

Börje Sellergren