Molecularly imprinted cryogel as a pH-responsive delivery system for doxorubicin

Evaluation of reproducible cryogel preparation based on automated image analysis using deep learning

Cryogels represent a class of porous sponge-like materials possessing unique properties including high-fidelity reproduction of tissue structure and maximized permeability. Their architecture is mainly based on an interconnected network of macropores that provides sufficient stability while allowing the movement of substances through the material. In most cryogel applications, the pore size is very important, especially when the material is used as a 3D scaffold for tissue culture, applied as a filter, or utilized as a membrane. In this study, poly(dimethylacrylamide-co-2-hydroxyethyl methacrylate) cryogels have been prepared by two preparation methods to investigate the reproducibility of homogeneous pore structures and pore sizes. Automated image analysis algorithms were developed to rapidly evaluate cryogel pore sizes based on scanning electron microscopy (SEM) images. The quantification approach contained a unique combination of classical and deep learning-based algorithms. To validate the accuracy of the two models, we compared the results obtained from automated SEM image analysis with those from manual pore size determinations and mercury intrusion porosimetry (MIP) measurements. Effect sizes were calculated to compare the results from manual and automated pore size measurements for the cryogel reproducibility series. 81% of the values obtained revealed only trivial differences, which strongly suggests that automated image analysis can reliably substitute the manual evaluation of cryogel pore sizes. The use of an adapted reactor setup yielded cryogels with heterogeneous morphologies in the absence of recognizable pore structures. With the conventional cryogel preparation using plastic syringes, the obtained cryogels represented highly reproducible morphologies and pore sizes in the range between 17 and 22 μm. Calculated effect sizes within the cryogel replicate series revealed only trivial differences between the obtained pore sizes in 83.5% or 99.4% of the data (classical approach and deep learning-based approach, respectively).

Comparative MIP sensor technique: photopolymerization or thermal polymerization for the sensitive determination of anticancer drug Regorafenib in different matrixes

Regorafenib (REG) is a diphenylurea derivative oral multikinase inhibitor. It plays an important role in the treatment of colorectal cancer, metastatic gastrointestinal stromal tumors, and hepatocellular carcinoma. Molecularly imprinted polymer (MIP) based glassy carbon electrodes (GCE) were fabricated using photopolymerization (PP) and thermal polymerization (TP) methods. The characterizations of the proposed sensors were investigated by electrochemical techniques, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). Several parameters were studied in detail for the optimum conditions of MIP-based sensors, such as dropping volume, photopolymerization and thermal polymerization durations, removal medium and time, and rebinding time. Both sensors' analytical validation and electroanalytical performance comparison were made in different REG concentrations ranging between 0.1 nM and 2.5 nM in standard solution and commercial human serum samples. The limit of detection (LOD) of PP-REG@MIP/GCE and TP-REG@MIP/GCE were 9.13 × 10-12 M and 1.44 × 10-11 M in standard solutions and 2.04 × 10-11 M and 2.02 × 10-11 M in serum samples, respectively. The applicability of the proposed sensors was tested using commercial human serum samples and pharmaceutical form of REG with high recovery values (PP-REG@MIP/GCE and TP REG@MIP/GCE sensors, 99.56-101.59%, respectively). The selectivity of the sensor for REG was investigated in the presence of similar molecules: Sorafenib, Sunitinib, Nilotinib, and Imatinib. The developed techniques and sensors checked the possible biological compounds and ions' effects and storage stability.

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.

Bio-Inspired Imprinting Materials for Biomedical Applications

Inspired by the recognition mechanism of biological molecules, molecular imprinting techniques (MITs) are imparted with numerous merits like excellent stability, recognition specificity, adsorption properties, and easy synthesis processes, and thus broaden the avenues for convenient fabrication protocol of bio-inspired molecularly imprinted polymers (MIPs) with desirable functions to satisfy the extensive demands of biomedical applications. Herein, the recent research progress made with respect to bio-inspired imprinting materials is discussed in this review. First, the underlying mechanism and basic components of a typical molecular imprinting procedure are briefly explored. Then, emphasis is put on the introduction of diverse MITs and novel bio-inspired imprinting materials. Following these two sections, practical applications of MIPs in the field of biomedical science are focused on. Last but not least, perspectives on the remaining challenges and future development of bio-inspired imprinting materials are presented.

p(HEMA)-RR241 hydrogel membranes with micron network for IgG depletion in proteomic studies

Serum proteins can generally be considered a good source for the illness' indication and are precious resources to detect diseases such as inflammation, cancer, diabetes, malnutrition, cardiovascular diseases, Alzheimer's, other autoimmune diseases, and infections. However, one of the biggest difficulties for proteomic studies is that the majority of serum protein mass consists of only a few proteins. Albumin and Immunoglobulin (IgG) constitute 80% of total serum protein. In this study, dye ligand affinity-based hydrogel membranes were proposed as new materials with micron mesh structures. Micron mesh p(HEMA) hydrogel membranes were synthesized by using the UV-photopolymerization method, then modified with Reactive Red 241 (RR241) dye ligand to increase the affinity towards IgG. Characterizations of synthesized micron mesh p(HEMA)-RR241 hydrogel membranes were also performed. It was demonstrated by the characterization studies that; the dye was successfully incorporated into the membrane structure with the amount of 119.38 mg/g. The hydrophilic property of the hydrogel membrane was demonstrated by swelling tests and the swelling value of dye modified membrane was found to be 8 times higher than that of the plain membrane. Micron network structure, as well as the porosity, were demonstrated with SEM/ESEM studies. Optimization of IgG adsorption conditions was also studied at different parameters (pH, temperature, ion strength, initial IgG concentration). Optimum pH, temperature, and ionic strength were found to be 6.5, 25 °C, 0.05 M, respectively, and the maximum IgG absorption value was 10.27 mg/g. Finally, it was shown that the proposed materials can be used repeatedly by 5 adsorption-desorption cycles.

Upgrading of bio‐separation and bioanalysis using synthetic polymers: Molecularly imprinted polymers (MIPs), cryogels, stimuli‐responsive polymers

Bio‐separation plays a crucial role in many areas. Different polymers are suitable for bio‐separation and are useful for applications in applications in both science and technology. Besides biopolymers, there are a broad spectrum of synthetic polymers with tailor‐made properties. The synthetic polymers are characterized by their charges, solubility, hydrophilicity/hydrophobicity, sensitivity to environmental conditions and stability. Furthermore, ongoing developments are of great interest on biodegradable polymers for the treatment of diseases. Smart polymers have gained great attention due to their unique characteristics especially emphasizing simultaneously changing their chemical and physical property upon exposure to changes in environmental conditions. In this review, methodologies applied in bio‐separation using synthetic polymers are discussed and efficient candidates are focused for the construction of synthetic polymers.

Design and Assessment of Biodegradable Macroporous Cryogels as Advanced Tissue Engineering and Drug Carrying Materials

Cryogels obtained by the cryotropic gelation process are macroporous hydrogels with a well-developed system of interconnected pores and shape memory. There have been significant recent advancements in our understanding of the cryotropic gelation process, and in the relationship between components, their structure and the application of the cryogels obtained. As cryogels are one of the most promising hydrogel-based biomaterials, and this field has been advancing rapidly, this review focuses on the design of biodegradable cryogels as advanced biomaterials for drug delivery and tissue engineering. The selection of a biodegradable polymer is key to the development of modern biomaterials that mimic the biological environment and the properties of artificial tissue, and are at the same time capable of being safely degraded/metabolized without any side effects. The range of biodegradable polymers utilized for cryogel formation is overviewed, including biopolymers, synthetic polymers, polymer blends, and composites. The paper discusses a cryotropic gelation method as a tool for synthesis of hydrogel materials with large, interconnected pores and mechanical, physical, chemical and biological properties, adapted for targeted biomedical applications. The effect of the composition, cross-linker, freezing conditions, and the nature of the polymer on the morphology, mechanical properties and biodegradation of cryogels is discussed. The biodegradation of cryogels and its dependence on their production and composition is overviewed. Selected representative biomedical applications demonstrate how cryogel-based materials have been used in drug delivery, tissue engineering, regenerative medicine, cancer research, and sensing.

Molecularly Imprinted Synthetic Antibodies: From Chemical Design to Biomedical Applications

Billions of dollars are invested into the monoclonal antibody market every year to meet the increasing demand in clinical diagnosis and therapy. However, natural antibodies still suffer from poor stability and high cost, as well as ethical issues in animal experiments. Thus, developing antibody substitutes or mimics is a long-term goal for scientists. The molecular imprinting technique presents one of the most promising strategies for antibody mimicking. The molecularly imprinted polymers (MIPs) are also called "molecularly imprinted synthetic antibodies" (MISAs). The breakthroughs of key technologies and innovations in chemistry and material science in the last decades have led to the rapid development of MISAs, and their molecular affinity has become comparable to that of natural antibodies. Currently, MISAs are undergoing a revolutionary transformation of their applications, from initial adsorption and separation to the rising fields of biomedicine. Herein, the fundamental chemical design of MISAs is examined, and then current progress in biomedical applications is the focus. Meanwhile, the potential of MISAs as qualified substitutes or even to transcend the performance of natural antibodies is discussed from the perspective of frontier needs in biomedicines, to facilitate the rapid development of synthetic artificial antibodies.

Advances in Molecularly Imprinted Systems: Materials, Characterization Methods and Analytical Applications

Introduction:

A molecular imprinting is one of the fascinating modification methods that employ molecules as targets to create geometric cavities for recognition of targets in the polymeric matrix. This method provides a broad versatility to imprint target molecules with different size, three-dimensional structure and physicochemical features. In contrast to the complex and timeconsuming laboratory surface modification procedures, this method offers a rapid, sensitive, inexpensive, easy-to-use, and selective approach for the diagnosis, screening and monitoring disorders. Owing to their unique features such as high selectivity, physical and chemical robustness, high stability, low-cost and reusability of this method, molecularly imprinted polymers have become very attractive materials and been applied in various applications from separation to detection.

Background:

The aims of this review are structured according to the fundamentals of molecularly imprinted polymers involving essential elements, preparation procedures and also the analytical applications platforms. Finally, the future perspectives to increase the development of molecularly imprinted platforms.

Methods:

A molecular imprinting is one of the commonly used modification methods that apply target as a recognition element itself and provide a wide range of versatility to replica other targets with a different structure, size, and physicochemical features. A rapid, easy, cheap and specific recognition approach has become one of the investigation areas on, especially biochemistry, biomedicine and biotechnology. In recent years, several technologies of molecular imprinting method have gained prompt development according to continuous use and improvement of traditional polymerization techniques.

Results:

The molecularly imprinted polymers with excellent performances have been prepared and also more exciting and universal applications have been recognized. In contrast to the conventional methods, the imprinted systems have superior advantages including high stability, relative ease and low cost of preparation, resistance to elevated temperature, and pressure and potential application to various target molecules. In view of these considerations, molecularly imprinted systems have found application in various fields of analytical chemistry including separation, purification, detection and spectrophotometric systems.

Conclusion:

Recent analytical methods are reported to develop the binding kinetics of imprinted systems by using the development of other technologies. The combined platforms are among the most encouraging systems to detect and recognize several molecules. The diversity of molecular imprinting methods was overviewed for different analytical application platforms. There is still a requirement of more knowledge on the molecular features of these polymers. A next step would further be the optimization of different systems with more homogeneous and easily reachable recognition sites to reduce the laborious in the accessibility in the three-dimensional polymeric materials in sufficient recognition features and also better selectivity and sensitivity for a wide range of molecules.

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.