Template recognition of protein-imprinted polymer surfaces

Molecularly Imprinted Ligand-Free Nanogels for Recognizing Bee Venom-Originated Phospholipase A2 Enzyme

In this study, ligand-free nanogels (LFNGs) as potential antivenom mimics were developed with the aim of preventing hypersensitivity and other side effects following massive bee attacks. For this purpose, poly (ethylene glycol) diacrylate was chosen as a main synthetic biocompatible matrix to prepare the experimental LFNGs. The overall concept uses inverse mini-emulsion polymerization as the main route to deliver nanogel caps with complementary cavities for phospholipase A2 (PLA2) from bee venom, created artificially with the use of molecular imprinting (MI) technologies. The morphology and the hydrodynamic features of the nanogels were confirmed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis. The following rebinding experiments evidenced the specificity of molecularly imprinted LFNG for PLA2, with rebinding capacities up to 8-fold higher compared to the reference non-imprinted nanogel, while the in vitro binding assays of PLA2 from commercial bee venom indicated that such synthetic nanogels are able to recognize and retain the targeted PLA2 enzyme. The results were finally collaborated with in vitro cell-viability experiments and resulted in a strong belief that such LFNG may actually be used for future therapies against bee envenomation.

Bioapplications of Nanomaterials

Nanobiotechnology is known as the application of nanoscaled techniques in biology which bridges natural science to living organism for improving the quality of life of humans. Nanotechnology was first issued in 1959 and has been rapidly developed, supplying numerous benefits to basic scientific academy and to clinical application including human healthcare, specifically in cancer therapy. This chapter discusses recent advances and potentials of nanotechnology in pharmaceutics, therapeutics, biosensing, bioimaging, and gene delivery that demonstrate the multifunctionality of nanotechnology.

Molecular recognition with soft biomaterials

Biomacromolecules and engineered materials can achieve molecular recognition if they engage their ligand with properly oriented and chemically complementary moieties. Recently, there has been significant interest in fabricating recognitive soft materials, which possess specific affinity for biological analytes. We present a summary and evaluation of current recognitive materials for biosensing, drug delivery, and regenerative medicine applications. We highlight the impact of material composition on the extent and specificity of ligand adsorption, citing new theoretical and empirical evidence. We conclude with a guide for synthesizing and characterizing novel recognitive materials, as well as recommendations for ligand selection and experimental design.

Molecular Imprinting of Macromolecules for Sensor Applications

Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.

Molecular Imprinting Techniques Used for the Preparation of Biosensors

Molecular imprinting is the technology of creating artificial recognition sites in polymeric matrices which are complementary to the template in their size, shape and spatial arrangement of the functional groups. Molecularly imprinted polymers (MIPs) and their incorporation with various transducer platforms are among the most promising approaches for detection of several analytes. There are a variety of molecular imprinting techniques used for the preparation of biomimetic sensors including bulk imprinting, surface imprinting (soft lithography, template immobilization, grafting, emulsion polymerization) and epitope imprinting. This chapter presents an overview of all of these techniques with examples from particular publications.

Molecularly imprinted polymer membranes and thin films for the separation and sensing of biomacromolecules

This review describes recent advances associated with the development of surface imprinting methods for the synthesis of polymeric membranes and thin films, which possess the capability to selectively and specifically recognize biomacromolecules, such as proteins and single- and double-stranded DNA, employing "epitope" or "whole molecule" approaches. Synthetic procedures to create different molecularly imprinted polymer membranes or thin films are discussed, including grafting/in situ polymerization, drop-, dip-, or spin-coating procedures, electropolymerization as well as micro-contact or stamp lithography imprinting methods. Highly sensitive techniques for surface characterization and analyte detection are described, encompassing luminescence and fluorescence spectroscopy, X-ray photoelectron spectroscopy, FTIR spectroscopy, surface-enhanced Raman spectroscopy, atomic force microscopy, quartz crystal microbalance analysis, cyclic voltammetry, and surface plasmon resonance. These developments are providing new avenues to produce bioelectronic sensors and new ways to explore through advanced separation science procedures complex phenomena associated with the origins of biorecognition in nature.

Photolithographic boronate affinity molecular imprinting: a general and facile approach for glycoprotein imprinting

Better than expected: With a regular boronic acid as the functional monomer, a general and facile approach for glycoprotein imprinting exhibited several highly favorable features that are beyond normal expectation, which make the prepared MIPs feasible for the recognition of trace glycoproteins in complicated real samples.

The influence of nanostructured materials on biointerfacial interactions

Control over biointerfacial interactions in vitro and in vivo is the key to many biomedical applications: from cell culture and diagnostic tools to drug delivery, biomaterials and regenerative medicine. The increasing use of nanostructured materials is placing a greater demand on improving our understanding of how these new materials influence biointerfacial interactions, including protein adsorption and subsequent cellular responses. A range of nanoscale material properties influence these interactions, and material toxicity. The ability to manipulate both material nanochemistry and nanotopography remains challenging in its own right, however, a more in-depth knowledge of the subsequent biological responses to these new materials must occur simultaneously if they are ever to be affective in the clinic. We highlight some of the key technologies used for fabrication of nanostructured materials, examine how nanostructured materials influence the behavior of proteins and cells at surfaces and provide details of important analytical techniques used in this context.

Critical review and perspective of macromolecularly imprinted polymers

Molecular recognition is a fundamental and ubiquitous process that is the driving force behind life. Natural recognition elements - including antibodies, enzymes, nucleic acids, and cells - exploit non-covalent interactions to bind to their targets with exceptionally strong affinities. Due to this unparalleled proficiency, scientists have long sought to mimic natural recognition pathways. One promising approach is molecularly imprinted polymers (MIPs), which are fully synthetic systems formed via the crosslinking of organic polymers in the presence of a template molecule, which results in stereo-specific binding sites for this analyte of interest. Macromolecularly imprinted polymers, those synthesized in the presence of macromolecule templates (>1500 Da), are of particular importance because they open up the field for a whole new set of robust diagnostic tools. Although the specific recognition of small-molecular-weight analytes is now considered routine, extension of these efficacious procedures to the protein regime has, thus far, proved challenging. This paper reviews the main approaches employed, highlights studies of interest with an emphasis on recent work, and offers suggestions for future success in the field of macromolecularly imprinted polymers.

Molecularly imprinted nanopatterns for the recognition of biological warfare agent ricin

Molecularly imprinted polymer (MIP) for biological warfare agent (BWA) ricin was synthesized using silanes in order to avoid harsh environments during the synthesis of MIP. The synthesized MIP was utilized for the recognition of ricin. The complete removal of ricin from polymer was confirmed by fluorescence spectrometer and SEM-EDAX. SEM and EDAX studies confirmed the attachment of silane polymer on the surface of silica gel matrix. SEM image of Ricin-MIP exhibited nanopatterns and it was found to be entirely different from the SEM image of non-imprinted polymer (NIP). BET surface area analysis revealed more surface area (227 m(2)/g) for Ricin-MIP than that of NIP (143 m(2)/g). In addition, surface area study also showed more pore volume (0.5010 cm(3)/g) for Ricin-MIP than that of NIP (0.2828 cm(3)/g) at 12 nm pore diameter confirming the presence of imprinted sites for ricin as the reported diameter of ricin is 12 nm. The recognition and rebinding ability of the Ricin-MIP was tested in aqueous solution. Ricin-MIP rebound more ricin when compared to the NIP. Chromatogram obtained with Ricin-MIP exhibited two peaks due to imprinting, however, chromatogram of NIP exhibited only one peak for free ricin. SDS-PAGE result confirmed the second peak observed in chromatogram of Ricin-MIP as ricin peak. Ricin-MIP exhibited an imprinting efficiency of 1.76 and it also showed 10% interference from the structurally similar protein abrin.

Protein-imprinted polysiloxane scaffolds

Molecular imprinting is a technique used to create specific recognition sites on the surface of materials. Although widely developed for chromatographic separation of small molecules, this approach has not been adequately investigated for biomaterial applications. Thus, the objective of these experiments was to explore the potential of molecular imprinting for creating biomaterials that preferentially bind specific proteins. Macroporous polysiloxane (silica) scaffolds were imprinted with either lysozyme or RNase A using sol-gel processing. The quantity of surface-accessible protein, which was related to the number of potential binding sites, was varied by changing the amount of protein loaded into the sol. Up to 62% of loaded protein was accessible. The amount of protein per unit surface area ranged from 0.3microgm(-2) for low loading of RNase to 152microgm(-2) for high loading of lysozyme. Protein-imprinted scaffolds were then evaluated for their ability to preferentially recognize the template biomolecule when incubated in mixtures containing both the imprinted protein and a competitor protein of comparable size (approximately 14kD). In solutions containing a single protein, up to 3.6 times more template bound compared with the competitor. Furthermore, in solutions containing equal amounts of both molecules, the porous scaffolds bound up to three times more template than the competitor protein, which is a level of preferential binding similar to values reported in the molecular imprinting literature for both organic and inorganic materials.

Static secondary ion mass spectrometry for biological and biomedical research

Static secondary ion mass spectrometry (SSIMS) is a capable of providing detailed atomic and molecular characterization of the surface chemistry of biological and biomedical materials. The technique is particularly suited to the detection and imaging of small molecules such as membrane lipids, metabolites, and drugs. A limit of detection in the ppm range and spatial resolution <1 microm can be obtained. Recent progress in instrumental developments, notably cluster ion beams, and the application of multivariate data analysis protocols, promise further advances. This chapter presents a brief overview of the theory and instrumentation of static secondary ion mass spectrometry followed by examples of a range of biological and biomedical applications. Because of the ultrahigh vacuum requirements and extreme surface sensitivity of the technique, appropriate sample preparation and handling is essential. These protocols, and the analysis methodology required to ensure high-quality, reliable data are described.

Formation of protein molecular imprints within Langmuir monolayers: a quartz crystal microbalance study

Protein imprinting leading to enhanced rebinding of ferritin to ternary lipid monolayers is demonstrated using a quartz crystal microbalance. Monolayers consisting of cationic dioctadecyldimethylammonium bromide, non-ionic methyl stearate, and poly(ethylene glycol) bearing phospholipids were imprinted with ferritin at the air/water interface of a Langmuir-Blodgett trough and transferred hydrated to hydrophobic substrates for study. This immobilization was shown by fluorescence correlation spectroscopy to significantly hinder any further diffusion of lipids, while rebinding studies demonstrated up to a six-fold increase in ferritin adsorption to imprinted versus control monolayers. A diminished rebinding of ferritin to its imprint was observed through pH reduction to below the protein isoelectric point, demonstrating the electrostatic nature of the interaction. Rebinding to films where imprint pockets remained occupied by the template protein was also minimal. Studies with a smaller acidic protein revealed the importance of the steric influence of poly(ethylene glycol) in forming the protein binding pockets, as albumin-imprinted monolayers showed low binding of ferritin, while ferritin-imprinted monolayers readily accommodated albumin. The controllable structure-function relationship and limitations of this system are discussed with respect to the application of protein imprinting in sensor development as well as fundamental studies of proteins at dynamic interfaces.

From 3D to 2D: a review of the molecular imprinting of proteins

Molecular imprinting is a generic technology that allows for the introduction of sites of specific molecular affinity into otherwise homogeneous polymeric matrices. Commonly this technique has been shown to be effective when targeting small molecules of molecular weight <1500, while extending the technique to larger molecules such as proteins has proven difficult. A number of key inherent problems in protein imprinting have been identified, including permanent entrapment, poor mass transfer, denaturation, and heterogeneity in binding pocket affinity, which have been addressed using a variety of approaches. This review focuses on protein imprinting in its various forms, ranging from conventional bulk techniques to novel thin film and monolayer surface imprinting approaches.

Using protein templates to direct the formation of thin-film polymer surfaces

Protein imprinted electrodes formed by the cyclic voltammetric deposition of conductive polymers, on screen-printed platinum supports, in the presence of target proteins have been fabricated. An initial layer of polypyrrole was used as a supporting polymer layer, upon which were formed two layers of polyaminophenylboronic acid. The first of these layers was non-imprinted and formed a barrier between the polypyrrole and the outer layer, which was deposited in the presence of a protein template (lysozyme or cytochrome c). After protein extraction, re-binding of the template proteins to their respective imprinted electrodes showed a distinct two-phase binding profile; whereas, binding to control polymers, made in the same way but without the addition of protein templates, showed progressive binding typical of non-specific recognition. Reductions in the observed current transmission due to bonding to the polymer surface of non-conductive protein have been used as a measure of re-binding. It was found that when challenged with 1 part per million protein in solution, the current reductions for the lysozyme and cytochrome c imprinted electrodes were 30.3 and 66.2%, respectively, compared to 4.5 and 29.9% for their respective control electrodes. All measurements carried out at -0.1 V with Ag/AgCl reference.

[New intelligent and targetted drug delivery systems. Pharmaceutical and biomedical applications]

Biomaterials are widely used in numerous medical applications. Chemical engineering has played a central role in this research and development. We review herein polymers as biomaterials, materials and approaches used in drug and protein delivery systems, materials used as scaffolds in tissue engineering, and nanotechnology and microfabrication techniques applied to biomaterials.

The microcontact imprinting of proteins: the effect of cross-linking monomers for lysozyme, ribonuclease A and myoglobin

The performance of molecularly imprinted polymers (MIPs) is of interest to researchers in the field of analytical chemistry, and in the pharmaceutical and food industries. Because the choice of the functional monomer(s) plays a key role in the selectivity of a MIP, the synthesis of an effective, tight-binding MIP can be difficult and time-consuming, involving the evaluation of the binding performance of MIPs of many different compositions. In this study, we report an express method combining molecular imprinting and microcontact printing techniques to prepare a polymer thin film as an artificial antibody. In addition to the microcontact printing technique, isothermal titration of monomers to proteins stamps was investigated to screen the functional monomer for MIPs. Finally, the importance of the choice of cross-linking monomers in MIPs was studied, and these studies suggest that monomers containing an optimal length PEG spacer give higher imprinting effectiveness. Several model antigens (lysozyme, ribonuclease A and myoglobin) were adsorbed on a cover glasses that were pretreated with hexamethyldisilazane (HMDS). These protein stamps were then contacted with different monomer solutions (cross-linking monomers) on a glass slide substrate. Photopolymerization yielded the molecularly imprinted polymer. This technique, analogous to microcontact printing, allows for the rapid, parallel synthesis of MIPs of different compositions, and requires very small volumes of monomers (ca. 4 microL). The technique also avoids potential solubility problems with the molecular targets. Of several cross-linking monomers screened, tetraethyleneglycol dimethacrylate (TEGDMA) gave the most selective lysozyme binding, while polyethyleneglycol 400 dimethacrylate (PEG400DMA) were most selective for ribonuclease A and myoglobin.

Nanotechnology - The New Frontier of Medicine

Molecular nanotechnology is destined to become the core technology in 21(st) century medicine. Nanotechnology mean, controlling biologically relevant structures with molecular precision. Nanomedicine is exploring how to use carbon buckyballs, dendrimers and other cleverly engineered nanoparticles in novel drugs to combat viruses, bacteria, cancer and delivery of drugs. Medical nanorobots will be of the size of a microbe, capable of self-replication, containing onboard sensors, computers, manipulators, pumps, pressure tanks and power supplies. Building such sophisticated molecular machine systems will require molecular manufacturing to using massively parallel assembly lines in nanofactories.

Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003

Over 1450 references to original papers, reviews and monographs have herein been collected to document the development of molecular imprinting science and technology from the serendipitous discovery of Polyakov in 1931 to recent attempts to implement and understand the principles underlying the technique and its use in a range of application areas. In the presentation of the assembled references, a section presenting reviews and monographs covering the area is followed by papers dealing with fundamental aspects of molecular imprinting and the development of novel polymer formats. Thereafter, literature describing attempts to apply these polymeric materials to a range of application areas is presented.

pH/Temperature - Sensitive Imprinted Ionic Poly(N-tert-butylacrylamide-co-acrylamide/maleic acid) Hydrogels for Bovine Serum Albumin

In this study, we have prepared pH/temperature-sensitive imprinted ionic poly(N-tert-butylacrylamide-co-acrylamide/maleic acid) [P(TBA-co-AAm/MA)] hydrogels for bovine serum albumin (BSA) by using molecular imprinting method. BSA adsorption from aqueous BSA solutions was investigated with two types of hydrogel systems prepared by non-imprinted and imprinted methods. Hydrogels imprinted with BSA showed higher adsorption capacity and specificity for BSA than hydrogels prepared by the usual procedure. At all studied conditions, the highest BSA adsorption was observed in the hydrogel imprinted with 8.63 wt.-% BSA. In addition, the imprinted hydrogels exhibited both for good selectivity BSA and high adsorption rate depending on the number of BSA-sized cavities. Adsorption studies showed that other stimuli, such as pH, temperature and initial BSA concentration also influenced the BSA adsorption capacity of both non-imprinted and imprinted hydrogels.

Enthalpy changes associated with protein binding to thin films

Molecularly imprinted thin films consisting of proteins embedded in polymerised aminophenyl boronic acid have been made on glass supports. The protein contents of the films have been optimised to achieve a maximum energy of interaction between the film and the native template. The fabrication of the films and the subsequent removal from their surfaces of the imprint proteins has been shown to be a facile and easily reproduced process. The enthalpy changes associated with the rebinding of the films with their original templates (lysozyme and cytochrome c) and with non-native templates has been examined by micro-calorimetry. The results demonstrate that thin films can be successfully imprinted as shown by the significant reduction in the enthalpy (DeltaH) observed when the films were rebound with proteins other than the original templates. Additionally, it was shown that after binding, non-template proteins could be removed by washing and a greater enthalpy again observed when the films were rebound with the native protein compared to that which had been found with the non-native protein.

Surface modification of interconnected porous scaffolds

Surface properties of scaffolds play an important role in cell adhesion and growth. Biodegradable poly(alpha-hydroxy acids) have been widely used as scaffolding materials for tissue engineering; however, the lack of functional groups is a limitation. In this work, gelatin was successfully immobilized onto the surface of poly(alpha-hydroxy acids) films and porous scaffolds by a new entrapment process. The surface composition and properties were examined using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectra (XPS), and contact angle measurements. Control over the amount of entrapped gelatin was achieved by varying the solvent composition, the duration of soaking, the concentration of gelatin in solution, and chemical crosslinking. The amount of entrapped gelatin increased with the ratio of dioxane/water in the solvent mixture used. Chemical crosslinking after physical entrapment considerably increased the amount of retained gelatin on the surface of poly(alpha-hydroxy acids). Osteoblasts were cultured on these films and scaffolds. The surface modification significantly improved cell attachment and proliferation. Cell numbers on the surface-modified films and scaffolds were significantly higher than those on controls 4 h and 1 day after cell seeding. The osteoblasts showed higher proliferation on surface-modified scaffolds than on the control during 4 weeks of in vitro cultivation. More collagen fibers and other cell secretions were deposited on the surface-modified scaffolds than on the control scaffolds. This novel surface treatment strategy provides a convenient and universal way to modify the surface properties of three-dimensional scaffolds and thus promote cell adhesion and proliferation for tissue engineering.

Biomimetic materials and micropatterned structures using iniferters

In the preparation of biomimetic materials it is often required that efficient methods of polymerization be used, often methods that can lead to biomimetic polymers with relatively narrow molecular weight distribution. Living radical polymerization techniques have successfully been used to create low polydispersity linear polymers by free-radical polymerizations. Although this technique slows down the polymerization of multifunctional monomers, there is little effect on the network structure due to the high concentration of pendent double bonds. There are applications of the living radical polymerization in the synthesis of block copolymers. Essentially, the technique involves polymerizing a single type of monomer first to create a macromonomer that is capable of acting as an initiator because of the reversible bond between the polymer end group and the terminating group. This terminating group may be a thiol or a halogen and, under the right conditions, will dissociate to form radicals. A second monomer is then added to the system and the polymerization proceeds with the second monomer chemically attached to the polymer of the first monomer. We review methods of creating biomimetic block copolymers using the iniferter radical polymerization technique. The block copolymers would be used in the synthesis of micropatterned polymer films for use in biomaterials and other biomedical applications.

Membrane separations using molecularly imprinted polymers

This review presents an overview on the promising field of molecularly imprinted membranes (MIM). The focus is onto the separation of molecules in liquid mixtures via membrane transport selectivity. First, the status of synthetic membranes and membrane separation technology is briefly summarized, emphasizing the need for novel membranes with higher selectivities. Innovative principles for the preparation of membranes with improved or novel functionality include self-assembly or supramolecular aggregation as well as the use of templates. Based on a detailed analysis of the literature, the main established preparation methods for MIM are outlined: simultaneous membrane formation and imprinting, or preparation of imprinted composite membranes. Then, the separation capability of MIM is discussed for two different types, as a function of their barrier structure. Microporous MIM can continuously separate mixtures based on facilitated diffusion of the template, or they can change their permeability in the presence of the template ("gate effect"). Macroporous MIM can be developed towards molecule-specific membrane adsorbers. Emerging further combinations of molecularly imprinted polymers (MIPs), especially MIP nanoparticles or microgels, with membranes and membrane processes are briefly outlined as well. Finally, the application potential for advanced MIM separation technologies is summarized.

Nanotechnology and medicine

Nanotechnology, or systems/device manufacture at the molecular level, is a multidisciplinary scientific field undergoing explosive development. The genesis of nanotechnology can be traced to the promise of revolutionary advances across medicine, communications, genomics and robotics. On the surface, miniaturisation provides cost effective and more rapidly functioning mechanical, chemical and biological components. Less obvious though is the fact that nanometre sized objects also possess remarkable self-ordering and assembly behaviours under the control of forces quite different from macro objects. These unique behaviours are what make nanotechnology possible, and by increasing our understanding of these processes, new approaches to enhancing the quality of human life will surely be developed. A complete list of the potential applications of nanotechnology is too vast and diverse to discuss in detail, but without doubt one of the greatest values of nanotechnology will be in the development of new and effective medical treatments (i.e., nanomedicine). This review focuses on the potential of nanotechnology in medicine, including the development of nanoparticles for diagnostic and screening purposes, artificial receptors, DNA sequencing using nanopores, manufacture of unique drug delivery systems, gene therapy applications and the enablement of tissue engineering.

Force spectroscopy study of the adhesion of plasma proteins to the surface of a dialysis membrane: role of the nanoscale surface hydrophobicity and topography

A mechanochemical study of the process of adhesion of plasma proteins to the surface of dialysis membranes was carried out with a scanning force microscope (SFM) in the force spectroscopy mode. Three representative blood plasma proteins (fibronectin, fibrinogen, and albumin) covalently were grafted to a SFM probe, and the adhesion forces of these proteins to cellulosic and synthetic dialysis membranes were measured. The experiment was tailored to apply a controlled load on the protein molecules adsorbed onto the surface in order to simulate the squeezing forces exerted on them during blood filtration. The de-adhesion forces, measured using this new approach for studying the interaction between a protein and dialysis membranes, suggest that the membrane's topography, at a nanometer scale, plays a critical role in the adhesion process. This result was strongly supported by parallel experiments performed on a flattened glass surface with the same dominant hydrophilic character as dialysis membranes. In contrast, a hydrophobic polystyrene surface led to de-adhesion forces at least one order of magnitude greater, overwhelming any possible shape recognition process between the protein molecules and the surface.

Spectroscopic anatomy of molecular-imprinting of cyclodextrin. Evidence for preferential formation of ordered cyclodextrin assemblies

The processes of molecular-imprinting of beta-cyclodextrin (beta-CyD) with cholesterol and stigmasterol (cross-linking agent = diisocyanate) have been analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectroscopy. These templates enormously promote the formation of dimers and trimers of beta-CyD, which are only inefficiently formed in their absence. These ordered assemblies are the guest-binding sites, in which two or three beta-CyD molecules cooperate to bind large steroids. Ordered assemblies are also formed when 2,6-di-O-methyl-beta-cyclodextrin is used in place of beta-CyD. Direct spectroscopic evidence for molecular-imprinting effect has been obtained. Molecular imprinting of CyDs is potent for tailor-made preparation of synthetic receptors for nanometer-scaled guests.