5-Fluorouracil delivery from metal-ion mediated molecularly imprinted cryogel discs

Cryogels: Advancing Biomaterials for Transformative Biomedical Applications

Cryogels, composed of synthetic and natural materials, have emerged as versatile biomaterials with applications in tissue engineering, controlled drug delivery, regenerative medicine, and therapeutics. However, optimizing cryogel properties, such as mechanical strength and release profiles, remains challenging. To advance the field, researchers are exploring advanced manufacturing techniques, biomimetic design, and addressing long-term stability. Combination therapies and drug delivery systems using cryogels show promise. In vivo evaluation and clinical trials are crucial for safety and efficacy. Overcoming practical challenges, including scalability, structural integrity, mass transfer constraints, biocompatibility, seamless integration, and cost-effectiveness, is essential. By addressing these challenges, cryogels can transform biomedical applications with innovative biomaterials.

Molecularly Imprinted Cryogels for the Selective Adsorption of Salicylic Acid

In this study, molecularly imprinted cryogels were fabricated for selective adsorption of salicylic acid. Cryogelation was performed at - 20 °C using a cationic monomer N,N-dimethylaminoethyl methacrylate as a functional monomer for salicylic acid. The morphology, swelling behaviors, and chemical structures of the cryogels were investigated. The general structure and porosities of cryogels were compared with the traditional hydrogels using field emission scanning electron microscopy (FE-SEM). The adsorption performance of cryogels toward salicylic acid was studied to investigate the optimal adsorption conditions. Adsorption capacity of the imprinted cryogels was 1.95 and 7.51 times higher than those of non-imprinted and bare PHEMA cryogels, respectively, due to the specific binding sites toward salicylic acid. Molecularly imprinted cryogels exhibited significant stability and reusability by keeping more than 85% of their adsorption capacity after ten regeneration cycles. Considering the fabrication process, adsorption capacity, selectivity, and reusability of the imprinted cryogels, these new materials could be utilized as a promising alternative for selective adsorption of drug molecules.

Preparation of Staphylococcal Protein A Imprinted Supermacroporous Cryogel Beads

Protein A is the most commonly used ligand in IgG purification due to its specific binding to the Fc receptor of most immunoglobulins, making it commercially important. Molecular imprinting is a method based on the selective recognition of various molecules. Molecular imprinted polymers are materials that are easy to prepare, durable, cheap and have molecular recognition capability. Cryogels are prepared by radical polymerization in a partially frozen environment. The unique structure of cryogels combined with osmotic, chemical and mechanical stability make them attractive chromatography matrices for a variety of biological compounds/specimens (plasmids, pathogens, cells). In this protocol, protein A imprinted supermacroporous poly(2-hydroxyethyl methacrylate) cryogels were prepared in spherical form for protein A purification. The characterization of the prepared cryogels were made by swelling test, scanning electron microscopy (SEM), Fourier transform infrared spectrophotometer (FTIR), and Brunauer-Emmett-Teller (BET) surface area analysis. After characterization, optimum conditions for protein A adsorption were determined in the batch system. The maximum protein A adsorption capacity was determined after optimization of the imprinted cryogels. Protein A relative selectivity coefficients of imprinted cryogels were examined for both Fc and protein G. Protein A was isolated from the bacterial cell wall using fast performance liquid chromatography (FPLC). The separated protein A was determined by sodium dodecyl sulfate gel electrophoresis (SDS-PAGE). In the last stage, the reusability of the cryogel was examined.

Advances in Molecularly Imprinted Polymers as Drug Delivery Systems

Despite the tremendous efforts made in the past decades, severe side/toxic effects and poor bioavailability still represent the main challenges that hinder the clinical translation of drug molecules. This has turned the attention of investigators towards drug delivery vehicles that provide a localized and controlled drug delivery. Molecularly imprinted polymers (MIPs) as novel and versatile drug delivery vehicles have been widely studied in recent years due to the advantages of selective recognition, enhanced drug loading, sustained release, and robustness in harsh conditions. This review highlights the design and development of strategies undertaken for MIPs used as drug delivery vehicles involving different drug delivery mechanisms, such as rate-programmed, stimuli-responsive and active targeting, published during the course of the past five years.

Injectable Cryogels in Biomedicine

Cryogels are interconnected macroporous materials that are synthesized from a monomer solution at sub-zero temperatures. Cryogels, which are used in various applications in many research areas, are frequently used in biomedicine applications due to their excellent properties, such as biocompatibility, physical resistance and sensitivity. Cryogels can also be prepared in powder, column, bead, sphere, membrane, monolithic, and injectable forms. In this review, various examples of recent developments in biomedical applications of injectable cryogels, which are currently scarce in the literature, made from synthetic and natural polymers are discussed. In the present review, several biomedical applications of injectable cryogels, such as tissue engineering, drug delivery, therapeutic, therapy, cell transplantation, and immunotherapy, are emphasized. Moreover, it aims to provide a different perspective on the studies to be conducted on injectable cryogels, which are newly emerging trend.

Antibacterial effect against both Gram-positive and Gram-negative bacteria via lysozyme imprinted cryogel membranes

The development of novel biocompatible and cost effective cryogel membrane which shows enhanced antimicrobial properties in order to use for several approaches such as wound dressing, scaffold or food packaging was aimed in this study. A super macro porous lysozyme imprinted cryogel membranes showing antibacterial effect against both Gram-positive and Gram-negative bacteria were prepared by using molecular imprinting technique. N-methacryloyl-(L)-histidine methyl ester (MAH) was used as the pseudo specific ligand and complexed with Cu⁺⁺ in order to provide metal ion coordination between MAH and template molecule (lysozyme). Comparing the antibacterial activity of different lysozyme concentrations, cryogel membranes were prepared in three different concentrations. To synthesize Poly (hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methylester) P(HEMA-MAH) cryogel membrane, free radical polymerization initiated by N, N, N', N'-tetramethylene diamine (TEMED) and ammonium persulfate (APS) was carried out at -12 °C. The characterization of the lysozyme imprinted cryogel membrane was accomplished by using scanning electron microscopy (SEM), swelling degree measurements and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) spectroscopy. The cytotoxicity test of produced membrane was performed by using mouse fibroblast cell line L929. The antibacterial activity of P(HEMA-MAH) lysozyme molecular imprinted [P(HEMA-MAH) Lyz-MIP] cryogel membranes against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) were determined by Kirby-Bauer membranes diffusion and viable cell counting methods. When the antibacterial effect of P(HEMA-MAH) Lyz-MIP cryogel membranes were evaluated, it was found that P(HEMA-MAH) Lyz-MIP cryogel membranes had stronger antibacterial effects against Gram-negative E. coli bacteria even in low lysozyme concentrations. In addition, 100% bacterial inhibition was detected for both of two bacteria at increasing lysozyme concentrations.

Preparation of lysozyme loaded gelatin microcryogels and investigation of their antibacterial properties

Antibacterial micron-sized cryogels, so-called microcryogels, were prepared by cryogelation of gelatin and integration of lysozyme. Gelation yield, specific surface area, macro-porosity and swelling degree of the microcryogels were examined in order to characterize their physical properties. MTT method was utilized to measure cell viability of the gelatin microcryogels with a period of 24, 48, and 72 h and no significant decrease was observed at 72 h. Apoptotic staining assay also showed high viability at 24, 48, 72 h in parallel with the control group. The antibacterial performances of the gelatin microcryogels against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli were examined. The results showed that the incorporation of lysozyme into gelatin microcryogels exhibited the antibacterial activity against S. aureus, B. subtilis, and E. coli, that may provide great potential for various applications in the biomedical industry.

Perspectives of Molecularly Imprinted Polymer-Based Drug Delivery Systems in Cancer Therapy

Despite the considerable effort made in the past decades, multiple aspects of cancer management remain a challenge for the scientific community. The severe toxicity and poor bioavailability of conventional chemotherapeutics, and the multidrug resistance have turned the attention of researchers towards the quest of drug carriers engineered to offer an efficient, localized, temporized, and doze-controlled delivery of antitumor agents of proven clinical value. Molecular imprinting of chemotherapeutics is very appealing in the design of drug delivery systems since the specific and selective binding sites created within the polymeric matrix turn these complex structures into value-added carriers with tunable features, notably high loading capacity, and a good control of payload release. Our work aims to summarize the present state-of-the art of molecularly imprinted polymer-based drug delivery systems developed for anticancer therapy, with emphasis on the particularities of the chemotherapeutics’ release and with a critical assessment of the current challenges and future perspectives of these unique drug carriers.

Challenges and Advances in the Fabrication of Monolithic Bioseparation Materials and their Applications in Proteomics Research

High-performance liquid chromatography integrated with tandem mass spectrometry (HPLC-MS/MS) has become a powerful technique for proteomics research. Its performance heavily depends on the separation efficiency of HPLC, which in turn depends on the chromatographic material. As the "heart" of the HPLC system, the chromatographic material is required to achieve excellent column efficiency and fast analysis. Monolithic materials, fabricated as continuous supports with interconnected skeletal structure and flow-through pores, are regarded as an alternative to particle-packed columns. Such materials are featured with easy preparation, fast mass transfer, high porosity, low back pressure, and miniaturization, and are next-generation separation materials for high-throughput proteins and peptides analysis. Herein, the recent progress regarding the fabrication of various monolithic materials is reviewed. Special emphasis is placed on studies of the fabrication of monolithic capillary columns and their applications in separation of biomolecules by capillary liquid chromatography (cLC). The applications of monolithic materials in the digestion, enrichment, and separation of phosphopeptides and glycopeptides from biological samples are also considered. Finally, advances in comprehensive 2D HPLC separations using monolithic columns are also shown.

Molecularly Imprinted Polymer-Based Microfluidic Systems for Point-of-Care Applications

Fast progress has been witnessed in the field of microfluidic systems and allowed outstanding approaches to portable, disposable, low-cost, and easy-to-operate platforms especially for monitoring health status and point-of-care applications. For this purpose, molecularly imprinted polymer (MIP)-based microfluidics systems can be synthesized using desired templates to create specific and selective cavities for interaction. This technique guarantees a wide range of versatility to imprint diverse sets of biomolecules with different structures, sizes, and physical and chemical features. Owing to their physical and chemical robustness, cost-friendliness, high stability, and reusability, MIP-based microfluidics systems have become very attractive modalities. This review is structured according to the principles of MIPs and microfluidic systems, the integration of MIPs with microfluidic systems, the latest strategies and uses for point-of-care applications and, finally, conclusions and future perspectives.

Analogs of C-type natriuretic peptide as a potential new non-surgical treatment strategy in knee osteoarthritis

Osteoarthritis (OA) is a common, chronic, progressive, and multifactorial musculoskeletal system disease affecting millions of people around the world. Despite the use of several treatment modalities, the search for a disease modifying drug continuous. Recent evidence suggest involvement of C-type natriuretic peptide (CNP) signaling in induction of chondroprotective pathways. A CNP analog (BMN 111) with an extended plasma half-life due to its neutral-endopeptidase resistance has shown to be pharmacologically active in achondroplasia enabling to hypothesize that BMN 111 may also be used as a treatment strategy in OA, in which CNP signaling has been suggested to be protective and/or reparative.

The influence of cross-linking agent onto adsorption properties, release behavior and cytotoxicity of doxorubicin-imprinted microparticles

Molecularly imprinted polymers (MIPs) are synthetic polymers that possess cavities selective towards their molecular templates and have found many applications in separation science, drug delivery, and catalysis. Here, we report the synthesis of doxorubicin-imprinted microparticles cross-linked with two different compounds (ethylene glycol dimethacrylate or trimethylolpropane trimethacrylate) and examination of their physicochemical properties. During the synthesis methacrylic acid was used as functional monomer and 2-hydroxyethyl methacrylate was added into polymerization mixture to increase hydrophilicity of the obtained materials and therefore improve interactions with aqueous release medium. The influence of initial concentration and contact time onto doxorubicin adsorption by obtained MIPs microparticles have been investigated. The microparticles obtained using ethylene glycol dimethacrylate as a cross-linker showed 3 times higher adsorption properties towards doxorubicin, than the ones obtained using trimethylolpropane trimethacrylate cross-linker. The release kinetics of doxorubicin from drug-loaded MIPs microparticles has been proven to be dependent upon cross-linker used and pH of the release medium. For drug-loaded MIPs microparticles obtained using both cross-linkers the IC₅₀ values measured for cancer cell were comparable to the ones measured for pure doxorubicin, whereas the cytotoxicity towards normal HDF cell lines was lower.

Supermacroporous Composite Cryogels in Biomedical Applications

Supermacroporous gels, called cryogels, are unique scaffolds that can be prepared by polymerization of monomer solution under sub-zero temperatures. They are widely used in many applications and have significant potential biomaterials, especially for biomedical applications due to their inherent interconnected supermacroporous structures and easy formation of composite polymers in comparison to other porous polymer synthesis techniques. This review highlights the fundamentals of supermacroporous cryogels and composite cryogels, and then comprehensively summarizes recent studies in preparation, functionalization, and utilization with mechanical, biological and physicochemical features, according to the biomedical applications. Furthermore, conclusions and outlooks are discussed for the use of these promising and durable supermacroporous composite cryogels.

Biomedical Applications of Polymeric Cryogels

The application of interconnected supermacroporous cryogels as support matrices for the purification, separation and immobilization of whole cells and different biological macromolecules has been well reported in literature. Cryogels have advantages over traditional gel carriers in the field of biochromatography and related biomedical applications. These matrices nearly mimic the three-dimensional structure of native tissue extracellular matrix. In addition, mechanical, osmotic and chemical stability of cryogels make them attractive polymeric materials for the construction of scaffolds in tissue engineering applications and in vitro cell culture, separation materials for many different processes such as immobilization of biomolecules, capturing of target molecules, and controlled drug delivery. The low mass transfer resistance of cryogel matrices makes them useful in chromatographic applications with the immobilization of different affinity ligands to these materials. Cryogels have been introduced as gel matrices prepared using partially frozen monomer or polymer solutions at temperature below zero. These materials can be produced with different shapes and are of interest in the therapeutic area. This review highlights the recent advances in cryogelation technologies by emphasizing their biomedical applications to supply an overview of their rising stars day to day.

Solvent effect on endosulfan adsorption onto polymeric arginine-methacrylate cryogels

Endosulfan is a persistent insecticide that is still used in some countries even though it is life-threatening and banned in the agricultural struggle. The solubility of pesticides in water is negligible. It is known that pesticides with better solubility in organic solvents have different solubility when the dielectric constants of these solvents are taken into account. The polymeric structure of arginine was modified with methacrylate to be a functional monomer, and it was immobilized on a solid support, poly(HEMA), and finally, poly(2-hydroxyethyl methacrylate-arginine methacrylate) was obtained and used as an effective adsorbent. The effect of organic solvents on endosulfan adsorption was investigated for the first time in the literature. Endosulfan was removed from alcohol media by using this polymeric structure synthesized by exploiting alcoho-phobic interaction in this work. Nuclear magnetic resonance (NMR), elemental analysis, and Fourier transform infrared spectroscopy (FTIR) methods were used for the structural characterization and therefore to prove successful synthesis of cryogels. Morphological characteristics were also investigated by scanning electron microscopy (SEM), an N₂ adsorption method, and swelling test. Adsorption experiments were carried out against varying interaction time and concentration parameters in the batch system. Since the alcohol used as a solvent has a pH value close to the ionic strength of drinking water, no change was made in the pH of the solution. Endosulfan molecules dissolved in solvents such as toluene, dichloromethane, acetone, and chloroform were removed using poly(HEMA-ArMA) cryogels to determine the solvent effect on the adsorption of endosulfan. As expected, the removal of endosulfan from the solvent toluene provided the best result. Although the adsorption in toluene is almost 9.5 times higher than that in ethanol, the use of toluene in the adsorption process due to its chemical structure is not feasible. Thus, experiments were carried out in ethanol.

Controlled release of mitomycin C from PHEMAH-Cu(II) cryogel membranes

Molecular imprinting technique was used for the preparation of antibiotic and anti-neoplastic chemotherapy drug (mitomycin C) imprinted cryogel membranes (MMC-ICM). The membranes were synthezied by using metal ion coordination interactions with N-methacryloyl-(l)-histidine methyl ester (MAH) functional monomer and template molecules (i.e. MMC). The 2-hydroxyethyl methacrylate (HEMA) monomer and methylene bisacrylamide (MBAAm) crosslinker were used for the preparation of mitomycin C imprinted cryogel membranes by radical suspension polymerization technique. The imprinted cryogel membranes were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR) and swelling degree measurements. Cytotoxicity of MMC-ICMs was investigated using mouse fibroblast cell line L929. Time-dependent release of MMC was demonstrated within 150 h from cryogel membranes. Cryogels demonstrated very high MMC loading efficiency (70-80%) and sustained MMC release over hours.

Thermo-responsive molecularly imprinted polymer containing magnetic nanoparticles: Synthesis, characterization and adsorption properties for curcumin

A novel intelligent thermoresponsive-magnetic molecularly imprinted polymer (TMMIP) nanocomposite based on N-isopropylacrylamide (NIPAM) & Fe₃O₄ was designed for the controlled & sustained release of Curcumin (CUR) with the ability to response external stimulus. The TMMIP nanocomposite was prepared using acryl functionalized β-cyclodextrin (β-CD) and NIPAM as functional monomers and CUR as target molecule. The recognition cavities which caused by host-guest interactions had direct influence to enhanced drug loading and sustained release of CUR. According to in-vitro release experiment in two different temperatures (below & above LCST of NIPAM) the prolonged & controlled release of CUR were observed. The release rate could be controlled by changing the temperature because of the phase transition behavior of NIPAM monomer. Also, the proposed biosensor displayed effective role in separation science, reasonable adsorption capacity (77mgg^-1), fast recognition (10min equilibration), selective extraction toward CUR in the presence of structural analogues and easily separation using external magnetic field. Moreover, the synthesized TMMIP was confirmed by various characterization.

Recognition of lysozyme using surface imprinted bacterial cellulose nanofibers

Here, we developed the lysozyme imprinted bacterial cellulose (Lyz-MIP/BC) nanofibers via the surface imprinting strategy that was designed to recognize lysozyme. This study includes the molecular imprinting method onto the surface of bacterial cellulose nanofibers in the presence of lysozyme by metal ion coordination, as well as further characterizations methods FTIR, SEM and contact angle measurements. The maximum lysozyme adsorption capacity of Lyz-MIP/BC nanofibers was found to be 71 mg/g. The Lyz-MIP/BC nanofibers showed high selectivity for lysozyme towards bovine serum albumin and cytochrome c. Overall, the Lyz-MIP/BC nanofibers hold great potential for lysozyme recognition due to the high binding capacity, significant selectivity and excellent reusability.

Molecularly imprinted cryogel membranes for mitomycin C delivery

In this study, cryogel-based implantable molecularly imprinted drug delivery systems were designed for the delivery of antineoplastic agent. Mitomycin C imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-l-glutamic acid) cryogel membranes were produced by free-radical bulk polymerization under partially frozen conditions. The membranes were characterized by swelling tests, Fourier transform infrared spectroscopy, scanning electron microscopy, surface area measurements and in vitro hemocompatibility tests. In vitro delivery studies were carried out to examine the effects of cross-linker ratio and template content. Mitomycin C imprinted cryogel membranes have megaporous structure (10-100 μm in diameter). The cumulative release of mitomycin C was decreased with increasing cross-linking agent ratio and increased with the amount of template in the cryogel structure. The nature of transport mechanism of the mitomycin C from the membranes was non-Fickian.

Molecularly Imprinted Membranes: Past, Present, and Future

More than 80 years ago, artificial materials with molecular recognition sites emerged. The application of molecular imprinting to membrane separation has been studied since 1962. Especially after 1990, such research has been intensively conducted by membranologists and molecular imprinters to understand the advantages of each technique with the aim of constructing an ideal membrane, which is still an active area of research. The present review aims to be a substantial, comprehensive, authoritative, critical, and general-interest review, placed at the cross section of two broad, interconnected, practical, and extremely dynamic fields, namely, the fields of membrane separation and molecularly imprinted polymers. This review describes the recent discoveries that appeared after repeated and fertile collisions between these two fields in the past three years, to which are added the worthy acknowledgments of pioneering discoveries and a look into the future of molecularly imprinted membranes. The review begins with a general introduction in membrane separation, followed by a short theoretical section regarding the basic principles of mass transport through a membrane. Following these general aspects on membrane separation, two principles of obtaining polymeric materials with molecular recognition properties are reviewed, namely, molecular imprinting and alternative molecular imprinting, followed the methods of obtaining and practical applications for the particular case of molecularly imprinted membranes. The review continues with insights into molecularly imprinted nanofiber membranes as a promising, highly optimized type of membrane that could provide a relatively high throughput without a simultaneous unwanted reduction in permselectivity. Finally, potential applications of molecularly imprinted membranes in a variety of fields are highlighted, and a look into the future of membrane separations is offered.

In vitro/in vivo study of novel anti-cancer, biodegradable cross-linked tannic acid for fabrication of 5-fluorouracil-targeting drug delivery nano-device based on a molecular imprinted polymer

The structure of a 5-fluorouracil carrier and fluorescent image of an animal after injection under a magnetic field.

From imprinting to microcontact imprinting-A new tool to increase selectivity in analytical devices

Molecular imprinting technology has been successfully applied to small molecular templates but a slow progress has been made in macromolecular imprinting owing to the challenges in natural properties of macromolecules, especially proteins. In this review, the macromolecular imprinting approaches are discussed with examples from recent publications. A new molecular imprinting strategy, microcontact imprinting is highlighted with its recent applications.