Evaluation of molecularly imprinted polymer based on HER2 epitope for targeted drug delivery in ovarian cancer mouse model

Molecular imprinting of miR-559 on a peptide-immobilized poly L-DOPA/silica core-shell and in vitro investigating its effects on HER2-positive breast cancer cells

In a significant percentage of breast cancers, increased expression of the HER2 receptor is seen and is associated with the spread and worsening of the disease. This research aims to investigate the effect of miR-559 (which targets HER2 mRNA) on SKBR3 breast cancer cells and the possibility of their effective delivery with polymeric nanoparticles and tumor-targeting peptides. L-DOPA monomers were polymerized on the surface of silica nanoparticles in the presence of miR-559 (as a molecular template for molecular imprinting) then an anti-HER2 peptide coupled to the surface of these polymeric nanocomposites (miR-NC-NL2), and the effects of this construct against a HER2-positive breast cancer cells (SKBR3 cells) investigated in vitro conditions. The results showed that miR-NC-NL2 is selective for HER2-positive cells and delivers the miR-559 to them in a targeted manner. miR-NC-NL2 decreased the proliferation of SKBR3 cells and reduced the expression and production of HER2 protein in these cells. Effective and targeted delivery of miR-559 to HER2-positive cancer cells by the miR-NC-NL2 promises the therapeutic potential of this nascent structure based on its inhibitory effect on cancer growth and progression. Of course, animal experiments require a better understanding of this structure's anti-tumor effects.

EGDMA- and TRIM-Based Microparticles Imprinted with 5-Fluorouracil for Prolonged Drug Delivery

Imprinted materials possess designed cavities capable of forming selective interactions with molecules used in the imprinting process. In this work, we report the synthesis of 5-fluorouracil (5-FU)-imprinted microparticles and their application in prolonged drug delivery. The materials were synthesized using either ethylene glycol dimethacrylate (EGDMA) or trimethylolpropane trimethacrylate (TRIM) cross-linkers. For both types of polymers, methacrylic acid was used as a functional monomer, whereas 2-hydroxyethyl methacrylate was applied to increase the final materials’ hydrophilicity. Adsorption isotherms and adsorption kinetics were investigated to characterize the interactions that occur between the materials and 5-FU. The microparticles synthesized using the TRIM cross-linker showed higher adsorption properties towards 5-FU than those with EGDMA. The release kinetics was highly dependent upon the cross-linker and pH of the release medium. The highest cumulative release was obtained for TRIM-based microparticles at pH 7.4. The IC₅₀ values proved that 5-FU-loaded TRIM-based microparticles possess cytotoxic activity against HeLa cell lines similar to pure 5-FU, whereas their toxicity towards normal HDF cell lines was ca. three times lower than for 5-FU.

Molecularly Imprinted Polymers as State-of-the-Art Drug Carriers in Hydrogel Transdermal Drug Delivery Applications

Molecularly Imprinted Polymers (MIPs) are polymeric networks capable of recognizing determined analytes. Among other methods, non-covalent imprinting has become the most popular synthesis strategy for Molecular Imprinting Technology (MIT). While MIPs are widely used in various scientific fields, one of their most challenging applications lies within pharmaceutical chemistry, namely in therapeutics or various medical therapies. Many studies focus on using hydrogel MIPs in transdermal drug delivery, as the most valuable feature of hydrogels in their application in drug delivery systems that allow controlled diffusion and amplification of the microscopic events. Hydrogels have many advantages over other imprinting materials, such as milder synthesis conditions at lower temperatures or the increase in the availability of biological templates like DNA, protein, and nucleic acid. Moreover, one of the most desirable controlled drug delivery applications is the development of stimuli-responsive hydrogels that can modulate the release in response to changes in pH, temperature, ionic strength, or others. The most important feature of these systems is that they can be designed to operate within a particular human body area due to the possibility of adapting to well-known environmental conditions. Therefore, molecularly imprinted hydrogels play an important role in the development of modern drug delivery systems.

The Evolution of Molecular Recognition: From Antibodies to Molecularly Imprinted Polymers (MIPs) as Artificial Counterpart

Molecular recognition is a useful property shared by various molecules, such as antibodies, aptamers and molecularly imprinted polymers (MIPs). It allows these molecules to be potentially involved in many applications including biological and pharmaceutical research, diagnostics, theranostics, therapy and drug delivery. Antibodies, naturally produced by plasma cells, have been exploited for this purpose, but they present noticeable drawbacks, above all production cost and time. Therefore, several research studies for similar applications have been carried out about MIPs and the main studies are reported in this review. MIPs, indeed, are more versatile and cost-effective than conventional antibodies, but the lack of toxicity studies and their scarce use for practical applications, make it that further investigations on this kind of molecules need to be conducted.

Hybrid Molecularly Imprinted Polymers: The Future of Nanomedicine?

Molecularly imprinted polymers (MIPs) have been widely used in nanomedicine in the last few years. However, their potential is limited by their intrinsic properties resulting, for instance, in lack of control in drug release processes or complex detection for in vivo imaging. Recent attempts in creating hybrid nanomaterials combining MIPs with inorganic nanomaterials succeeded in providing a wide range of new interesting properties suitable for nanomedicine. Through this review, we aim to illustrate how hybrid molecularly imprinted polymers may improve patient care with enhanced imaging, treatments, and a combination of both.

Epitope-imprinted polymers: Design principles of synthetic binding partners for natural biomacromolecules

Molecular imprinting (MI) has been explored as an increasingly viable tool for molecular recognition in various fields. However, imprinting of biologically relevant molecules like proteins is severely hampered by several problems. Inspired by natural antibodies, the use of epitopes as imprinting templates has been explored to circumvent those limitations, offering lower costs and greater versatility. Here, we review the latest innovations in this technology, as well as different applications where MI polymers (MIPs) have been used to target biomolecules of interest. We discuss the several steps in MI, from the choice of epitope and functional monomers to the different production methods and possible applications. We also critically explore how MIP performance can be assessed by various parameters. Last, we present perspectives on future breakthroughs and advances, offering insights into how MI techniques can be expanded to new fields such as tissue engineering.

Targeted delivery of paclitaxel by NL2 peptide-functionalized on core-shell LaVO4: Eu3@ poly (levodopa) luminescent nanoparticles

Targeted drug delivery enhances drug efficiency and selectivity without affecting normal cells. Luminescent nanoparticles can be used for tumor imaging as well as selective tumor targeting for drug delivery. In this research, LaVO4 :Eu3+ was synthesized, the luminescent nanocrystal was coated by surface polymerization of levodopa in the presence of Paclitaxel (PTX), and then NL2 peptide was coupled on the surface of polymer-coated luminescent nanoparticles. Next, the capability of the modified drug was examined by in vitro and in vivo experiments. MTT assay on SK-BR-3 cell line (as breast cancer cells) and fluorescent microscopy results indicate that this modification decreases significantly drug toxicity and increases its selectivity. In addition, in vivo experiments confirm more capability of the NL2-functionalized nanocomposite for reducing tumor size, drug distribution in the body, and more aggregation of PTX in tumor tissue. Overall, it is concluded that tumor imaging is possible using luminescent LaVO4 :Eu3+ core and NL2 peptide increases significantly the specificity of PTX in combination with a functionalized luminescent polymeric carrier.

Molecularly Imprinted Polymer Nanogels for Protein Recognition: Direct Proof of Specific Binding Sites by Solution STD and WaterLOGSY NMR Spectroscopies

Molecularly imprinted polymers (MIPs) are tailor-made synthetic antibodies possessing specific binding cavities designed for a target molecule. Currently, MIPs for protein targets are synthesized by imprinting a short surface-exposed fragment of the protein, called epitope or antigenic determinant. However, finding the epitope par excellence that will yield a peptide "synthetic antibody" cross-reacting exclusively with the protein from which it is derived, is not easy. We propose a computer-based rational approach to unambiguously identify the "best" epitope candidate. Then, using Saturation Transfer Difference (STD) and WaterLOGSY NMR spectroscopies, we prove the existence of specific binding sites created by the imprinting of this peptide epitope in the MIP nanogel. The optimized MIP nanogel could bind the epitope and cognate protein with a high affinity and selectivity. The study was performed on Hepatitis A Virus Cell Receptor-1 protein, also known as KIM-1 and TIM-1, for its ubiquitous implication in numerous pathologies.

Advances in epitope molecularly imprinted polymers for protein detection: a review

Epitope molecularly imprinted polymers (EMIPs) are novel imprinted materials using short characteristic peptides as templates rather than entire proteins. To be specific, the amino acid sequence of the template peptide is the same as an exposed N- or C-terminus of a target protein, or its amino acid composition and sequence replicate a similar conformational arrangement as the same amino acid residues on the surface of the target protein. EMIPs have a good application prospect in protein research. Herein, we focus on classification of epitope imprinting techniques, methods of epitope immobilization on matrix materials including boronate affinity immobilization, covalent bonding immobilization, physical adsorption immobilization and metal ion chelation immobilization, and application of EMIPs in peptides, proteins, target imaging and target therapy fields. Finally, the main problems and future development are summarized.

Molecularly Imprinted Polymer Nanoparticles: An Emerging Versatile Platform for Cancer Therapy

Molecularly imprinted polymers (MIPs) are chemically synthesized affinity materials with tailor-made binding cavities complementary to the template molecules in shape, size, and functionality. Recently, engineering MIP-based nanomedicines to improve cancer therapy has become a rapidly growing field and future research direction. Because of the unique properties and functions of MIPs, MIP-based nanoparticles (nanoMIPs) are not only alternatives to current nanomaterials for cancer therapy, but also hold the potential to fill gaps associated with biological ligand-based nanomedicines, such as immunogenicity, stability, applicability, and economic viability. Here, we survey recent advances in the design and fabrication of nanoMIPs for cancer therapy and highlight their distinct features. In addition, how to use these features to achieve desired performance, including extended circulation, active targeting, controlled drug release and anti-tumor efficacy, is discussed and summarized. We expect that this minireview will inspire more advanced studies in MIP-based nanomedicines for cancer therapy.

Molecular Imprinting Strategies for Tissue Engineering Applications: A Review

Tissue Engineering (TE) represents a promising solution to fabricate engineered constructs able to restore tissue damage after implantation. In the classic TE approach, biomaterials are used alongside growth factors to create a scaffolding structure that supports cells during the construct maturation. A current challenge in TE is the creation of engineered constructs able to mimic the complex microenvironment found in the natural tissue, so as to promote and guide cell migration, proliferation, and differentiation. In this context, the introduction inside the scaffold of molecularly imprinted polymers (MIPs)—synthetic receptors able to reversibly bind to biomolecules—holds great promise to enhance the scaffold-cell interaction. In this review, we analyze the main strategies that have been used for MIP design and fabrication with a particular focus on biomedical research. Furthermore, to highlight the potential of MIPs for scaffold-based TE, we present recent examples on how MIPs have been used in TE to introduce biophysical cues as well as for drug delivery and sequestering.

In Vitro Targeting of NL2 Peptide Bounded on Poly L-DOPA Coated Graphene Quantum Dot

Chemotherapy using drug delivery systems (DDS) can target cancer cells selectively and without affecting normal cells. In this paper, NL2 peptide as a tumor targeted peptide was bonded on the surface of poly 3,4-Dihydroxy-L-phenylalanine (Poly L-DOPA) graphene quantum dots (GQD), which was imprinted by Doxorubicin (DOX). The synthesized nanocomposite was characterized by Fourier-transform infrared spectroscopy (FTIR) and particle size was determined by dynamic light scattering (DLS) and Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). DOX release from synthesized nano-composite was investigated spectrophotometrically. Also, the toxicity and selectivity of NL2-GQD-NC on SK-BR-3 cell line were evaluated. FTIR and DLS experiment confirm the successful synthesis of Poly L-DOPA coated graphene quantum dots and their uniform particles. In vitro studies have shown that NL2-GQD-NC attached more to SK-BR-3 cells than NL2-free nanocomposites (GQD-NC). After attaching the cells could be imaged due to the presence of GQD particles and DOX release was accomplished in the tumor cells.

Developments of Smart Drug-Delivery Systems Based on Magnetic Molecularly Imprinted Polymers for Targeted Cancer Therapy: A Short Review

Cancer therapy is still a huge challenge, as especially chemotherapy shows several drawbacks like low specificity to tumor cells, rapid elimination of drugs, high toxicity and lack of aqueous solubility. The combination of molecular imprinting technology with magnetic nanoparticles provides a new class of smart hybrids, i.e., magnetic molecularly imprinted polymers (MMIPs) to overcome limitations in current cancer therapy. The application of these complexes is gaining more interest in therapy, due to their favorable properties, namely, the ability to be guided and to generate slight hyperthermia with an appropriate external magnetic field, alongside the high selectivity and loading capacity of imprinted polymers toward a template molecule. In cancer therapy, using the MMIPs as smart-drug-delivery robots can be a promising alternative to conventional direct administered chemotherapy, aiming to enhance drug accumulation/penetration into the tumors while fewer side effects on the other organs. Overview: In this review, we state the necessity of further studies to translate the anticancer drug-delivery systems into clinical applications with high efficiency. This work relates to the latest state of MMIPs as smart-drug-delivery systems aiming to be used in chemotherapy. The application of computational modeling toward selecting the optimum imprinting interaction partners is stated. The preparation methods employed in these works are summarized and their attainment in drug-loading capacity, release behavior and cytotoxicity toward cancer cells in the manner of in vitro and in vivo studies are stated. As an essential issue toward the development of a body-friendly system, the biocompatibility and toxicity of the developed drug-delivery systems are discussed. We conclude with the promising perspectives in this emerging field. Areas covered: Last ten years of publications (till June 2020) in magnetic molecularly imprinted polymeric nanoparticles for application as smart-drug-delivery systems in chemotherapy.

Selective Targeted Drug Delivery Mechanism via Molecular Imprinted Polymers in Cancer Therapeutics

Artificial receptor-like structures such as molecular imprinted polymers (MIPs) are biomimetic molecules are used to replicate target specific antibody-antigen mechanism. In MIPs, selective binding of template molecule can be significantly correlated with lock and key mechanism, which play a major role in the drug delivery mechanism. The MIPs are biocompatible with high efficiency and are considered in several drug delivery and biosensor applications besides continuous and controlled drug release leading to better therapeutics. There is a need to explore the potential synthetic methods to improve MIPs with respect to the imprinting capacity in cancer therapeutics. In this review, we focus on MIPs as drug delivery mechanism in cancer and the challenges related to their synthesis and applications.

RAFT coupling chemistry: a general approach for post-functionalizing molecularly imprinted polymers synthesized by radical polymerization

Herein we describe a straightforward protocol for the surface functionalization of free-radically synthesized imprinted nanoparticles via polymer grafting.

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.

Epitope Imprinting Technology: Progress, Applications, and Perspectives toward Artificial Antibodies

Epitope imprinting is a promising tool to generate antibody-like specific recognition sites. Recently, because of the ease of obtaining templates, the flexibility in selecting monomers, their resistance to harsh environments, and the high specificity toward targets, epitope-imprinted materials have attracted much attention in various fields, such as bioanalysis, clinical therapy, and pharmacy. Here, the discussion is focused on the current representative epitope imprinting technologies, including epitope bulk imprinting and epitope surface imprinting. Moreover, the application of epitope-imprinted materials to the recognition of peptides, proteins, and cells is reviewed. Finally, the remaining challenges arising from the intrinsic properties of epitope imprinting are discussed, and future development in the field is prospected.

Progress in Molecularly Imprinted Polymers for Biomedical Applications

Background:

Molecularly Imprinted Polymers (MIPs), a type of biomimetic materials have attracted considerable interest owing to their cost-effectiveness, good physiochemical stability, favorable specificity and selectivity for target analytes, and long shelf life. These materials are able to mimic natural recognition entities, including biological receptors and antibodies, providing a versatile platform to achieve the desirable functionality for various biomedical applications.

Objective:

In this review article, we introduce the most recent development of MIPs to date. We first highlight the advantages of using MIPs for a broad range of biomedical applications. We then review their various methods of synthesis along with their latest progress in biomedical applications, including biosensing, drug delivery, cell imaging and drug discovery. Lastly, the existing challenges and future perspectives of MIPs for biomedical applications are briefly discussed.

Conclusion:

We envision that MIPs may be used as potential materials for diverse biomedical applications in the near future.

Molecularly imprinted polymers by thiol–yne chemistry: making imprinting even easier

Molecularly imprinted polymers (MIPs) are synthetic, bio-mimetic materials with recognition properties on a par with those of antibodies, which feature superior physical and chemical stability.

The molecularly imprinted polymer essentials: curation of anticancer, ophthalmic, and projected gene therapy drug delivery systems

The development of polymeric materials as drug delivery systems has advanced from systems that rely on classical passive targeting to carriers that can sustain the precisely controlled release of payloads upon physicochemical triggers in desired microenvironment. Molecularly imprinted polymers (MIP), materials designed to capture specific molecules based on their molecular shape and charge distribution, are attractive candidates for fulfilling these purposes. In particular, drug-imprinted polymers coupled with active targeting mechanisms have been explored as potential drug delivery systems. In this review, we have curated important recent efforts in the development of drug-imprinted polymers in a variety of clinical applications, especially oncology and ophthalmology. MIP possesses properties that may complement the traditional delivery systems of these two disciplines, such as passive enhanced permeability and retention effect (EPR) in cancer tumors, and passive drug diffusion in delivering ophthalmic therapeutics. Furthermore, the prospects of MIP integration with the emerging gene therapies will be discussed.