In this work, an innovative and accurate affinity capillary electrophoresis (ACE) method was set up to monitor the complexation of aqueous MIP nanogels (NGs) with model cancer-related antigens. Using α2,6′- and α2,3′-sialyllactose as oversimplified cancer biomarker-mimicking templates, NGs were synthesized and characterized in terms of size, polydispersity, and overall charge. A stability study was also carried out in order to select the best storage conditions and to ensure product quality. After optimization of capillary electrophoresis conditions, injection of MIP NGs resulted in a single, sharp, and efficient peak. The mobility shift approach was applied to quantitatively estimate binding affinity, in this case resulting in an association constant of K ≈ 106 M–1. The optimized polymers further displayed a pronounced discrimination between the two sialylated sugars. The newly developed ACE protocol has the potential to become a very effective method for nonconstrained affinity screening of NG in solution, especially during the NG development phase and/or for a final accurate quantitation of the observed binding.

We describe a facile method to prepare water-compatible molecularly imprinted polymer nanogels (MIP NGs) as synthetic antibodies against target glycans. Three different phenylboronic acid (PBA) derivatives were explored as monomers for the synthesis of MIP NGs targeting either α2,6- or α2,3-sialyllactose, taken as oversimplified models of cancer-related sT and sTn antigens. Starting from commercially available 3-acrylamidophenylboronic acid, also its 2-substituted isomer and the 5-acrylamido-2-hydroxymethyl cyclic PBA monoester derivative were initially evaluated by NMR studies. Then, a small library of MIP NGs imprinted with the α2,6-linked template was synthesized and tested by mobility shift Affinity Capillary Electrophoresis (msACE), to rapidly assess an affinity ranking. Finally, the best monomer 2-acrylamido PBA was selected for the synthesis of polymers targeting both sialyllactoses. The resulting MIP NGs display an affinity constant≈10⁶ M⁻¹ and selectivity towards imprinted glycans. This general procedure could be applied to any non-modified carbohydrate template possessing a reducing end.

N-Acetylneuraminic acid and its α2,3/α2,6-glycosidic linkages with galactose (Neu5Ac-Gal) are major carbohydrate antigen epitopes expressed in various pathological processes, such as cancer, influenza, and SARS-CoV-2. We here report a strategy for the synthesis and binding investigation of molecularly imprinted polymers (MIPs) toward α2,3 and α2,6 conformations of Neu5Ac-Gal antigens. Hydrophilic imprinted monoliths were synthesized from melamine monomer in the presence of four different templates, namely, N-acetylneuraminic acid (Neu5Ac), N-acetylneuraminic acid methyl ester (Neu5Ac-M), 3′-sialyllactose (3SL), and 6′-sialyllactose (6SL), in a tertiary solvent mixture at temperatures varying from −20 to +80 °C. The MIPs prepared at cryotemperatures showed a preferential affinity for the α2,6 linkage sequence of 6SL, with an imprinting factor of 2.21, whereas the α2,3 linkage sequence of 3SL resulted in nonspecific binding to the polymer scaffold. The preferable affinity for the α2,6 conformation of Neu5Ac-Gal was evident also when challenged by a mixture of other mono- and disaccharides in an aqueous test mixture. The use of saturation transfer difference nuclear magnetic resonance (STD-NMR) on suspensions of crushed monoliths allowed for directional interactions between the α2,3/α2,6 linkage sequences on their corresponding MIPs to be revealed. The Neu5Ac epitope, containing acetyl and polyalcohol moieties, was the major contributor to the sequence recognition for Neu5Ac(α2,6)Gal(β1,4)Glc, whereas contributions from the Gal and Glc segments were substantially lower.

The use of polymerizable hosts in anion imprinting has led to powerful receptors with high oxyanion affinity and specificity in both aqueous and non-aqueous environments. As demonstrated in previous reports, a carefully tuned combination of orthogonally interacting binding groups, for example, positively charged and neutral hydrogen bonding monomers, allows receptors to be constructed for use in either organic or aqueous environments, in spite of the polymer being prepared in non-competitive solvent systems. We here report on a detailed experimental design of phenylphosphonic and benzoic acid-imprinted polymer libraries prepared using either urea-or thiourea-based host monomers in the presence or absence of cationic comonomers for charge-assisted anion recognition. A comparison of hydrophobic and hydrophilic crosslinking monomers allowed optimum conditions to be identified for oxyanion binding in non-aqueous, fully aqueous, or high-salt media. This showed that recognition improved with the water content for thiourea-based molecularly imprinted polymers (MIPs) based on hydrophobic EGDMA with an opposite behavior shown by the polymers prepared using the more hydrophilic crosslinker PETA. While the affinity of thiourea-based MIPs increased with the water content, the opposite was observed for the oxourea counterparts. Binding to the latter could however be enhanced by raising the pH or by the introduction of cationic amine-or Na+-complexing crown ether-based comonomers. Use of high-salt media as expected suppressed the amine-based charge assistance, whereas it enhanced the effect of the crown ether function. Use of the optimized receptors for removing the ubiquitous pesticide glyphosate from urine finally demonstrated their practical utility.

Aberrant sialic acid expression is one of the key indicators of pathological processes. This acidic saccharide is overexpressed in tumor cells and is a potent biomarker. Development of specific capture tools for various sialylated targets is an important step for early cancer diagnosis. However, sialic acid recognition by synthetic hosts is often complicated due to the competition for the anion binding by their counterions, such as Na+ and K+. Here we report on the design of a sialic acid receptor via simultaneous recognition of both the anion and cation of the target analyte. The polymeric receptor was produced using neutral (thio)urea and crown ether based monomers for simultaneous complexation of sialic acid's carboxylate group and its countercation. Thiourea and urea based functional monomers were tested both in solution by 1H NMR titration and in a polymer matrix system for their ability to complex the sodium salt of sialic acid alone and in the presence of crown ether. Combination of both orthogonally acting monomers resulted in higher affinities for the template in organic solvent media. The imprinted polymers displayed enhanced sialic acid recognition driven to a significant extent by the addition of the macrocyclic cation host. The effect of various counterions and solvent systems on the binding affinities is reported. Binding of K+, Na+ and NH4+ salts of sialic acid exceeded the uptake of bulky lipophilic salts. Polymers imprinted with sialic or glucuronic acids displayed a preference for their corresponding templates and showed a promising enrichment of sialylated peptides from the tryptic digest of glycoprotein bovine fetuin.

Aberrant glycosylation has been proven to correlate with various diseases including cancer. An important alteration in cancer progression is an increased level of sialylation, making sialic acid one of the key constituents in tumor-specific glycans and an interesting biomarker for a diversity of cancer types. Developing molecularly imprinted polymers (MIPs) with high affinity toward sialic acids is an important task that can help in early cancer diagnosis. In this work, the glycospecific MIPs are produced using cooperative covalent/noncovalent imprinting. We report here on the fundamental investigation of this termolecular imprinting approach. This comprises studies of the relative contribution of orthogonally interacting functional monomers and their synergetic behavior and the choice of different counterions on the molecular recognition properties for the sialylated targets. Combining three functional monomers targeting different functionalities on the template led to enhanced imprinting factors (IFs) and selectivities. This apparent cooperative effect was supported by H-1 NMR and fluorescence titrations of monomers with templates or template analogs. Moreover, highlighting the role of the template counterion use of tetrabutylammonium (TBA) salt of sialic acid resulted in better imprinting than that of sodium salts supported by both in solution interaction studies and in MIP rebinding experiments. The glycospecific MIPs display high affinity for sialylated targets, with an overall low binding of other nontarget saccharides.

Glycosylation plays an important role in various pathological processes such as cancer. One key alteration in the glycosylation pattern correlated with cancer progression is an increased level as well as changes in the type of sialylation. Developing molecularly-imprinted polymers (MIPs) with high affinity for sialic acid able to distinguish different glycoforms such as sialic acid linkages is an important task which can help in early cancer diagnosis. Sialyllactose with alpha 2,6 ' vs. alpha 2,3 ' sialic acid linkage served as a model trisaccharide template. Boronate chemistry was employed in combination with a library of imidazolium-based monomers targeting the carboxylate group of sialic acid. The influence of counterions of the cationic monomers and template on their interactions was investigated by means of H-1 NMR titration studies. The highest affinities were afforded using a combination of Br- and Na+ counterions of the monomers and template, respectively. The boronate ester formation was confirmed by MS and H-1/B-11 NMR, indicating 1 : 2 stoichiometries between sialyllactoses and boronic acid monomer. Polymers were synthesized in the form of microparticles using boronate and imidazolium monomers. This combinatorial approach afforded MIPs selective for the sialic acid linkages and compatible with an aqueous environment. The molecular recognition properties with respect to saccharide templates and glycosylated targets were reported.

Sialic acids are an important family of monosaccharides that are typically found as terminal moieties of glycans. Aberrant sialylation has been proven to correlate with various diseases including cancer. Glycosylation analysis is complex due to high diversityof the glycan isomers and their low abundance. Antibodies and lectins are commonly used in glycan purification and enrichment. However, high cost, poor availability, and limitation in storage/testing conditions hinders their application on a broader scale. This thesis is focused on the development of alternative glycan specific receptors with their potential applications in glycomics and cell imaging. The underlying technique for producing the synthetic receptors is molecular imprinting. Highly complementary binding sites are formed by fixing pre-ordered template/functional monomer complexes into a highly crosslinked polymer matrix. Fundamental investigation of this intermolecular imprinting approach in the imprinting of glycosylated targets is reported here. The core of this study focuses on the elucidation of relative contribution of orthogonally interacting functional monomers, their structural tuning and the importance of monomer, solvent and counterion choice on the imprinting. Molecularly imprinted polymers (MIPs) are developed as particles of different sizes for glycan/glycopeptide enrichment applications or combined with fluorescent reportergroups for use as glycan imaging nanolabels. Special attention is given to the improvement of sialic acid MIP selectivities toward particular structures associated with cancer biomarkers. Development of MIPs against such complex targets includes design of linkage selective MIPs with comprehensive studies of the affinities and selectivities of the final glycan specific materials.

The design of hosts for either cations or anions is complicated due to the competition for binding by the host or guest counterions. Imprinting relying on self-assembly offers the possibility to stabilize the guest and its counterion in a favorable geometry. We here report on a comprehensive supramolecular approach to anion receptor design relying on concurrent recognition of both anion and cation. This was achieved by high order complex imprinting of the disodium salt of phenyl-phosphonic acid in combination with neutral urea and sodium ion selective 18-crown-6 monomers. The polymers displayed enhanced affinity for the template or inorganic phosphate or sulfate in competitive aqueous buffers, with affinity and selectivity increasing with increasing ionic strength. The presence of engineered sites for both ionic species dramatically increases the salt uptake in strongly competitive media such as brine.

Cancer är en term som används för cirka 200 olika sjukdomar. Det de alla har gemensamt är att cellerna i kroppen börjar delas okontrollerat. 2018 fanns det 18 miljoner cancerfall över hela världen. I Sverige kommer ungefär varje tredje person att diagnostiseras med en cancersjukdom någon gång under sin livstid.

Det är en stor utmaning för vetenskapen att hitta sätt att diagnostisera och behandla dessa sjukdomar. På Malmö universitet arbetar en ny generation kemister, fysiker och biologer tillsammans i två internationella nätverk, BioCapture och GlycoImaging. Deras forskning fokuserar på att utforma antikroppar, plastkulor, som ska upptäcka cancerceller i ett tidigt skede. Kulorna är dessutom billiga att producera.

De två projekten samordnas av Börje Sellergren och Anette Gjörloff Wingren, som utbildar och handleder 19 doktorander. Utställningen Fighting Cancer with Plastic Bullets belyser doktorandernas tvärvetenskapliga arbete och deras betydelse för cancerforskningen. Biblioteket har fått bidrag av Sten K Johnsons stiftelse för att producera utställningen.

Cancer is a term used for about 200 different diseases. What they all have in common is that the cells in the body start to divide uncontrollably. In 2018 there were 18 million cancer cases around the world. In Sweden, approximately every third person will be diagnosed with a cancer disease at some point during their lifetime.A major challenge for science is to find ways to diagnose and treat these diseases. At Malmö university a new generation of chemists, physicists and biologists work in two international networks, BioCapture and GlycoImaging. Their research focus on designing plastic antibodies, bullets. The bullets are cheap to produce and aim to detect cancer cells at an early stage.

The two projects are coordinated by Börje Sellergren and Anette Gjörloff Wingren, who train and tutor 19 PhD students. This exhibition highlights the interdisciplinary work of the PhD’s and their importance for the cancer research.