General strategy for designing functionalized magnetic microspheres for different bioapplications

Co-immobilization of β-agarase and α-agarase for degradation of agarose to prepare bioactive 3,6-anhydro-L-galactose

Agarose from biomass can be used to synthesize the rare sugar 3,6-anhydro-L-galactose (L-AHG), and the new synthesis route and functional properties of L-AHG have always been the focus of research. Here we developed a novel method to co-immobilize Aga50D and BpGH117 onto streptavidin-coated magnetic nanoparticles and achieved the conversion of agarose to bioactive L-AHG in one pot. Results showed that enzymes were successfully immobilized on the carrier. The activity of co-immobilized enzymes was 2.5-fold higher than that of single immobilized enzymes. Compared with free enzymes, co-immobilized enzymes exhibited enhanced thermal stability. The co-immobilized enzymes retained 79.45 % relative activity at 40 °C for 3 h, while the free enzymes only possessed 21.40 % residual activity. After eight cycles, the co-immobilized enzymes still retained 73.47 % of the initial activity. After silica gel chromatography, the purity of L-AHG obtained by co-immobilized enzymes hydrolysis reached 83.02 %. Furthermore, bioactivity experiments demonstrated that L-AHG displayed better antioxidant and antibacterial effects than neoagarobiose. L-AHG had broad-spectrum antibacterial activity, while neoagarobiose and D-galactose did not show an obvious antibacterial effect. This study provides a feasible method for the production of L-AHG by a co-immobilized multi-enzyme system and confirms that L-AHG plays a key role in the bioactivity of neoagarobiose.

Solid-phase extraction with the functionalization of calcium-sensing receptors onto magnetic microspheres as an affinity probe can capture ligands selectively from herbal extract

Magnetic solid phase extraction with the functionalization of protein onto micro- or nano-particles as a probe is favorable for the discovery of new drugs from complicated natural products. Herein, we aimed to develop a rapid method by immobilizing halogenated alkane dehalogenase (Halo)-tagged calcium-sensing receptor (CaSR) directly out of crude cell lysates onto the surface of magnetic microspheres (MM) with no need to purify protein. Thereby we achieved CaSR-functionalized MM for revealing adsorption characteristics of agonist neomycin and screening ligands from herbal medicine Radix Astragali (RA). About 43.87 mg CaSR could be immobilized per 1 g MM within 30 min, and the acquired CaSR-functionalized MM showed good stability and activity for 4 weeks. The maximum adsorption capacity of neomycin on CaSR-functionalized MM was determined as 4.70 × 10-4 ~ 3.96 × 10-4 mol/g within 277 ~ 310 K, and its adsorption isotherm characteristics described best by the Temkin model were further validated using isothermal titration calorimetry. It was inferred that CaSR's affinity for neomycin was driven by electrostatic forces in a spontaneous process when the system reached an equilibrium state. Moreover, the ligands from the RA extract were screened, three of which were assigned as astragaloside IV, ononin, and calycosin based on HPLC-MS. Our findings demonstrated that the functionalization of a receptor onto magnetic materials designed as an affinity probe has the capability to recognize its agonist and capture the ligands selectively from complex matrices like herbs.

New opportunities for RGD-engineered metal nanoparticles in cancer

The advent of nanotechnology has opened new possibilities for bioimaging. Metal nanoparticles (such as gold, silver, iron, copper, etc.) hold tremendous potential and offer enormous opportunities for imaging and diagnostics due to their broad optical characteristics, ease of manufacturing technique, and simple surface modification. The arginine-glycine-aspartate (RGD) peptide is a three-amino acid sequence that seems to have a considerably greater ability to adhere to integrin adhesion molecules that exclusively express on tumour cells. RGD peptides act as the efficient tailoring ligand with a variety of benefits including non-toxicity, greater precision, rapid clearance, etc. This review focuses on the possibility of non-invasive cancer imaging using metal nanoparticles with RGD assistance.

An In Situ Study on Nanozyme Performance to Optimize Nanozyme-Strip for Aβ Detection

The nanozyme-strip is a novel POCT technology which is different from the conventional colloidal gold strip. It primarily utilizes the catalytic activity of nanozyme to achieve a high-sensitivity detection of target by amplifying the detection signal. However, previous research has chiefly focused on optimizing nanozyme-strip from the perspective of increasing nanozyme activity, little is known about other physicochemical factors. In this work, three sizes of Fe₃O₄ nanozyme and three sizes of CoFe₂O₄ nanozyme were used to investigate the key factors of nanozyme-strip for optimizing and improving its detection performance. We found that three sizes of Fe₃O₄ nanozyme all gather at the bottom of the nitrocellulose (NC) membrane, and three sizes of CoFe₂O₄ nanozyme migrate smoothly on the NC membrane, respectively. After color development, the surface of NC membranes distributed with CoFe₂O₄ peroxidase nanozymes had significant color change. Experimental results show that CoFe₂O₄ nanozymes had better dispersity than Fe₃O₄ nanozymes in an aqueous solution. We observed that CoFe₂O₄ nanozymes with smaller particle size migrated to the middle of the NC membrane with a higher number of particles. According to the results above, 55 ± 6 nm CoFe₂O₄ nanozyme was selected to prepare the nanozyme probe and achieved a highly sensitive detection of Aβ42Os on the nanozyme-strip. These results suggest that nanozyme should be comprehensively evaluated in its dispersity, the migration on NC membrane, and the peroxidase-like activity to determine whether it can be applied to nanozyme-strip.

Biosensing Using Magnetic Particle Detection Techniques

Magnetic particles are widely used as signal labels in a variety of biological sensing applications, such as molecular detection and related strategies that rely on ligand-receptor binding. In this review, we explore the fundamental concepts involved in designing magnetic particles for biosensing applications and the techniques used to detect them. First, we briefly describe the magnetic properties that are important for bio-sensing applications and highlight the associated key parameters (such as the starting materials, size, functionalization methods, and bio-conjugation strategies). Subsequently, we focus on magnetic sensing applications that utilize several types of magnetic detection techniques: spintronic sensors, nuclear magnetic resonance (NMR) sensors, superconducting quantum interference devices (SQUIDs), sensors based on the atomic magnetometer (AM), and others. From the studies reported, we note that the size of the MPs is one of the most important factors in choosing a sensing technique.

Ultrasensitive Detection of Viable Enterobacter sakazakii by a Continual Cascade Nanozyme Biosensor

Recent outbreaks of life-threatening neonatal infections linked to Enterobacter sakazakii (ES) heightened the need to develop rapid and ultrasensitive detection strategies, especially those capable of determining the viable cells. This study introduced a continual cascade nanozyme biosensor for the detection of viable ES based on propidium monoazide (PMA), loop-mediated isothermal amplification (LAMP), and Nanozyme strip. The ompA gene of ES was determined using FITC-modified and BIO-modified primers in the LAMP process. LAMP combined with PMA treatment was applied for distinguishing the viable from the dead state of ES. Then, using Fe₃O₄ magnetic nanoparticles as a nanozyme probe, a magnetic nanoparticle (MNP)-based immunochromatographic strip (Nanozyme strip) was further employed for amplifying signal to allow visual detection and quantification by a strip reader. The LAMP products were sandwiched between the anti-FITC and the anti-BIO, and the accumulation of the Fe₃O₄ magnetic nanoparticles enabled the visual detection of ES. The detection limit of the nanozyme biosensor was improved by 10 CFU/mL compared with previously reported techniques, and the whole manipulation process was much faster (within 1 h) and simpler (without specialist facilities). Hence, the developed continual cascade nanozyme biosensor has provided a rapid, ultrasensitive, and simple tool for on-site detection of viable ES.

Noninvasive monitoring of early antiangiogenic therapy response in human nasopharyngeal carcinoma xenograft model using MRI with RGD-conjugated ultrasmall superparamagnetic iron oxide nanoparticles

Purpose

Arginine-glycine-aspartic acid (RGD)-based nanoprobes allow specific imaging of integrin αvβ3, a protein overexpressed during angiogenesis. Therefore, this study applied a novel RGD-coupled, polyacrylic acid (PAA)-coated ultrasmall superparamagnetic iron oxide (USPIO) (referred to as RGD-PAA-USPIO) in order to detect tumor angiogenesis and assess the early response to antiangiogenic treatment in human nasopharyngeal carcinoma (NPC) xenograft model by magnetic resonance imaging (MRI).

Materials and methods

The binding specificity of RGD-PAA-USPIO with human umbilical vein endothelial cells (HUVECs) was confirmed by Prussian blue staining and transmission electron microscopy in vitro. The tumor targeting of RGD-PAA-USPIO was evaluated in the NPC xenograft model. Later, mice bearing NPC underwent MRI at baseline and after 4 and 14 days of consecutive treatment with Endostar or phosphate-buffered saline (n=10 per group).

Results

The specific uptake of the RGD-PAA-USPIO nanoparticles was mainly dependent on the interaction between RGD and integrin αvβ3 of HUVECs. The tumor targeting of RGD-PAA-USPIO was observed in the NPC xenograft model. Moreover, the T2 relaxation time of mice in the Endostar-treated group decreased significantly compared with those in the control group both on days 4 and 14, consistent with the immunofluorescence results of CD31 and CD61 (P<0.05).

Conclusion

This study demonstrated that the magnetic resonance molecular nanoprobes, RGD-PAA-USPIOs, allow noninvasive in vivo imaging of tumor angiogenesis and assessment of the early response to antiangiogenic treatment in NPC xenograft model, favoring its potential clinical translation.

Silk Fiber as the Support and Reductant for the Facile Synthesis of Ag-Fe₃O₄ Nanocomposites and Its Antibacterial Properties

We report a facile and environmentally friendly approach to prepare Ag-Fe₃O₄-silk fiber nanocomposites. The Ag-Fe₃O₄-silk fiber acts as: (i) a biocompatible support for the silver nanoparticles; and (ii) a reducing agent for the silver ions. Neither additional reducing agents nor toxic organic solvents were used during the preparation process. The Ag-Fe₃O₄-silk fiber nanocomposites can be actuated by a small household magnet and have high antibacterial activities against both Escherichia coli and Staphylococcus aureus. These nanocomposites could be easily recycled without a decrease in their antibacterial activities due to the synergistic effects between the Ag NPs and Fe₃O₄ NPs with large amounts of active sites.

Fabrication of hierarchical composite microspheres of copper-doped Fe3O4@P4VP@ZIF-8 and their application in aerobic oxidation

Copper-doped Fe₃O₄@P4VP@ZIF-8 composite microspheres were fabricated for application in the highly efficient aerobic oxidation of alcohols and epoxidation of olefins.

Magnetic resonance imaging of folic acid-coated magnetite nanoparticles reflects tissue biodistribution of long-acting antiretroviral therapy

Regimen adherence, systemic toxicities, and limited drug penetrance to viral reservoirs are obstacles limiting the effectiveness of antiretroviral therapy (ART). Our laboratory’s development of the monocyte-macrophage-targeted long-acting nanoformulated ART (nanoART) carriage provides a novel opportunity to simplify drug-dosing regimens. Progress has nonetheless been slowed by cumbersome, but required, pharmacokinetic (PK), pharmacodynamics, and biodistribution testing. To this end, we developed a small magnetite ART (SMART) nanoparticle platform to assess antiretroviral drug tissue biodistribution and PK using magnetic resonance imaging (MRI) scans. Herein, we have taken this technique a significant step further by determining nanoART PK with folic acid (FA) decorated magnetite (ultrasmall superparamagnetic iron oxide [USPIO]) particles and by using SMART particles. FA nanoparticles enhanced the entry and particle retention to the reticuloendothelial system over nondecorated polymers after systemic administration into mice. These data were seen by MRI testing and validated by comparison with SMART particles and direct evaluation of tissue drug levels after nanoART. The development of alendronate (ALN)-coated magnetite thus serves as a rapid initial screen for the ability of targeting ligands to enhance nanoparticle-antiretroviral drug biodistribution, underscoring the value of decorated magnetite particles as a theranostic tool for improved drug delivery.

Renal interstitial fibrosis induced by high-dose mesoporous silica nanoparticles via the NF-κB signaling pathway

Previous studies have indicated that the nephrotoxicity induced by mesoporous silica nanoparticles (MSNs) is closely related to inflammation. Nuclear factor kappa B (NF-κB), a common rapid transcription factor associated with inflammation, plays an important role in the process of many kidney diseases. Acute toxicity assessment with a high-dose exposure is critical for the development of nanoparticle, as a part of standardized procedures for the evaluation of their toxicity. The present study was undertaken to observe the acute toxicity, predict the potential target organs of MSNs injury, and test the hypothesis that the NF-κB pathway plays a role in mediating the acute kidney injury and renal interstitial fibrosis in mice induced by MSNs. Balb/c mice were intraperitoneally injected with MSNs at concentrations of 150, 300, or 600 mg/kg. All of the animals were euthanized 2 and 12 days after exposure, and the blood and kidney tissues were collected for further studies. In vitro, the cytotoxicity, fibrosis markers, and NF-κB pathway were measured in a normal rat kidney cell line (NRK-52E). Acute kidney injury was induced by MSNs in mice after 2 days, some renal tubules regenerated and renal interstitial fibrosis was also observed. The expression of fibrosis markers and the nuclear translocation of NF-κB p65 in the kidney homogenates increased after exposure to MSNs. The in vitro study showed that MSNs cause cytotoxicity in NRK-52E cells and increased the expression of fibrosis markers. In addition, the NF-κB pathway could be induced, and inhibition of the NF-κB pathway could alleviate the fibrosis caused by MSNs. We conclude that inflammation is a major effector of the acute kidney toxicity induced by MSNs and results in renal interstitial fibrosis, which is mediated by the NF-κB signaling pathway.

Synthesis and characterization of surface-modified Fe3O4 super-paramagnetic nanoparticles

Aqueous dispersion and stability of Fe3O4 nanoparticles remain an issue unresolved since aggregation of naked iron nanoparticles in water. In this study, we successfully synthesized different Fe3O4 super-paramagnetic nanoparticles which were modified by three kinds of materials [DSPE-MPEG2000, TiO2 and poly acrylic acid (PAA)] and further detected their characteristics. Transmission electron microscopy (TEM) clearly showed sizes and morphology of the four kinds of nanoparticles. X-ray diffraction (XRD) proved successfully coating of the three kinds of nanoparticles and their structures were maintained. Vibrating sample magnetometer (VSM) verified that their magnetic properties fitted for the super-paramagnetic function. More importantly, the particle size analysis indicated that Fe3O4@PAA had a better size distribution, biocompatibility, stability and dispersion than the other two kinds of nanoparticles. In addition, using CNE2 cells as a model, we found that all nanoparticles were nontoxic. Taken together, our data suggest that Fe3O4@PAA nanoaparticles are superior in the application of biomedical field among the four kinds of Fe3O4 nanoparticles in the future.

Facile and green synthesis of core-shell structured magnetic chitosan submicrospheres and their surface functionalization

Submicrometer-sized magnetite colloid nanocrystal clusters (MCNCs) provide a new avenue for constructing uniformly sized and highly magnetic composite submicrospheres. Herein, a facile and eco-friendly method is described for the synthesis of Fe3O4@poly(acrylic acid) (PAA)/chitosan (CS) core-shell submicrospheres using MCNCs bearing carboxyl groups as the magnetic cores. It is based on the self-assembly of positively charged CS chains on the surface of the oppositely charged MCNCs dispersed in the aqueous solution containing acrylic acid (AA) and a cross-linker N,N'-methylenebis(acrylamide) (MBA), followed by radical induced cross-linking copolymerization of AA and MBA along the CS chains. The resulting polymer shell comprises a medium shell of cross-linked PAA/CS polyelectrolyte complexes and an outer shell of protonated CS chains. It was found that the shell thickness could be tuned by varying either the concentration of radical initiator or the molar ratio of AA to aminoglucoside units of CS. To the surface of thus obtained Fe3O4@PAA/CS particles, Au nanoparticles, a variety of functional groups such as fluorescein, carboxyl, quaternary ammonium, and aliphatic bromide, and even functional polymer chains were successfully introduced. Therefore, such Fe3O4@PAA/CS submicrospheres may be used as versatile magnetic functional scaffolds in biorelated areas like bioseparation and medical assay, considering the unique features of CS like nontoxicity and biocompatibility.

RGD-conjugated iron oxide magnetic nanoparticles for magnetic resonance imaging contrast enhancement and hyperthermia

The purpose of this study was to develop a specific targeting magnetic nanoparticle probe for magnetic resonance imaging and therapy in the form of local hyperthermia. Carboxymethyl dextran-coated ultrasmall superparamagnetic iron oxide nanoparticles with carboxyl groups were coupled to cyclic arginine-glycine-aspartic peptides for integrin α(v)β₃ targeting. The particle size, magnetic properties, heating effect, and stability of the arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide were measured. The arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide demonstrates excellent stability and fast magneto-temperature response. Magnetic resonance imaging signal intensity of Bcap37 cells incubated with arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide was significantly decreased compared with that incubated with plain ultrasmall superparamagnetic iron oxide. The preferential uptake of arginine-glycine-aspartic-ultrasmall superparamagnetic iron oxide by target cells was further confirmed by Prussian blue staining and confocal laser scanning microscopy.

Sonochemical Synthesis of Silica Coated Super Paramagnetic Iron Oxide Nanoparticles

Superparamagnetic iron oxide nanoparticles (SPION) of sizes 5 to10 nm were synthesized by the co-precipitation method. They are coated with silica nanoparticles using sonication method. The SPION was produced under the optimum pH of 10, peptized in acidic medium and redispersed in water. The silica nanoparticles were produced through the Stöbermethod. Sonochemical coating of silica nanoparticle on the SPION was successfulat a pH value lower than 5. Otherwise, at higher pH value (but lower than point zero charge (PZC)), the SPION were found to be unstable. Fast hydrolysis of triethoxyvinylsilane(TEVS) shows that silica forms its own particles without coating onto the surfaces of the SPION. Under optimized experimental condition, sonochemical method of coating silica nanoparticles onto the SPION can be considered as an alternative for effective and prompt method that rely mainly on pH of the suspension.

CD146, a multi-functional molecule beyond adhesion

CD146 is a cell adhesion molecule (CAM) that is primarily expressed at the intercellular junction of endothelial cells. CD146 was originally identified as a tumor marker for melanoma (MCAM) due to its existence only in melanoma but not in the corresponding normal counterpart. However CD146 is not just a CAM for the inter-cellular and cell-matrix adhesion. Recent evidence indicates that CD146 is actively involved in miscellaneous processes, such as development, signaling transduction, cell migration, mesenchymal stem cells differentiation, angiogenesis and immune response. CD146 has increasingly become an important molecule, especially identified as a novel bio-marker for angiogenesis and for cancer. Here we have reviewed the dynamic research of CD146, particularly newly identified functions and the underlying mechanisms of CD146.

Dextran-coated magnetic supports modified with a biomimetic ligand for IgG purification

Dextran-coated iron oxide magnetic particles modified with ligand 22/8, a protein A mimetic ligand, were prepared and assessed for IgG purification. Dextran was chosen as the agent to modify the surface of magnetic particles by presenting a negligible level of nonspecific adsorption. For the functionalization of the particles with the affinity ligand toward antibodies, three methods have been explored. The optimum coupling method yielded a theoretical maximum capacity for human IgG calculated as 568 ± 33 mg/g and a binding affinity constant of 7.7 × 10⁴ M⁻¹. Regeneration, recycle and reuse of particles was also highly successful for five cycles with minor loss of capacity. Moreover, this support presented specificity and effectiveness for IgG adsorption and elution at pH 11 directly from crude extracts with a final purity of 95% in the eluted fraction.

Noninvasive monitoring of orthotopic glioblastoma therapy response using RGD-conjugated iron oxide nanoparticles

Noninvasive imaging techniques have been considered important strategies in the clinic to monitor tumor early response to therapy. In the present study, we applied RGD peptides conjugated to iron oxide nanoparticles (IONP-RGD) as contrast agents in magnetic resonance imaging (MRI) to noninvasively monitor the response of a vascular disrupting agent VEGF(121)/rGel in an orthotopic glioblastoma model. RGD peptides were firstly coupled to IONPs coated with a crosslinked PEGylated amphiphilic triblock copolymer. In vitro binding assays confirmed that cellular uptake of particles was mainly dependent on the interaction between RGD and integrin α(v)β(3) of human umbilical vein endothelial cells (HUVEC). The tumor targeting of IONP-RGD was observed in an orthotopic U87 glioblastoma model. Finally, noninvasive monitoring of the tumor response to VEGF(121)/rGel therapy at early stages of treatment was successfully accomplished using IONP-RGD as a contrast agent for MRI, a superior method over common anatomical approaches which are based on tumor size measurements. This preclinical study can accelerate anticancer drug development and promote clinical translation of nanoprobes.

Pathological mechanisms of liver injury caused by continuous intraperitoneal injection of silica nanoparticles

Crystalline silica is well known to induce chronic lung inflammation by inhalation that can progress to silicosis. Recently, we reported that silica nanoparticles (SN) cause more damage to liver instead of lung when they enter the body by intravenous injection. However, this mechanism is still unclear. In the present study, liver damages caused by mesoporous hollow silica nanoparticles (MHSNs) were demonstrated after continuous intraperitoneal injection into mice twice a week for 6 weeks. The administration of MHSNs at 50 mg/kg increased liver injury markers in serum, such as alanine aminotransferase (ALT), inflammatory cytokines interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α). Histological analysis revealed lymphocytic infiltration and silicotic nodular like lesions in liver. Collagen fibers were observed around the silicotic nodular like lesion, and hydroxyproline level in liver was also increased dramatically. We also found that activated kupffer cells (KCs) played a key role in the liver damage caused by SNs similar to alveolar macrophage in the process of silicosis. These suggest that the mechanism of liver damage caused by SNs is in consonance with the occurrence of silicosis. These findings may provide useful information for the further toxicity and bioapplication research of nanoparticles.

Functionalization of inorganic nanoparticles for bioimaging applications

Modern biomedical imaging technologies have led to significant advances in diagnosis and therapy. Because most disease processes occur at the molecular and cellular levels, researchers continue to face challenges in viewing and understanding these processes precisely and in real time. The ideal imaging resolution would be in nanometers, because most biological processes take place on this length scale. Therefore, the functionalization of nanoparticles (NPs) and their use in therapeutic and diagnostic applications are of great interest. Molecular and cellular imaging agents made from inorganic NPs have been developed to probe such biological events noninvasively. The conjugation of tiny NPs with specific biomolecules allows researchers to target the desired location, reduce overall toxicity, and boost the efficiency of the imaging probes. In this Account, we review recent research on the functionalization of NPs for bioimaging applications. Several types of NPs have been employed for bioimaging applications, including metal (Au, Ag), metal oxide (Fe(3)O(4)), and semiconductor nanocrystals (e.g. quantum dots (QDs) and magnetic quantum dots (MQDs)). The preparation of NPs for bioimaging applications can include a variety of steps: synthesis, coating, surface functionalization, and bioconjugation. The most common strategies of engineering NP surfaces involve physical adsorption or chemisorption of the desired ligands onto the surface. Chemisorption or covalent linkages are preferred, and the coated NPs should possess high colloidal stability, biocompatibility, water solubility, and functional groups for further bioconjugation. Many of the functionalization techniques that have been reported in the literature suffer from limitations such as complex synthesis steps, poor biocompatibility, low stability, and hydrophobic products. Coating strategies based on chemisorption and ligand exchange often provide a better way to tailor the surface properties of NPs. After conjugation with the appropriate targeting ligands, antibodies, or proteins, the NPs may exhibit highly selective binding, making them useful for fluorescence imaging, magnetic resonance imaging (MRI), positron emission tomography (PET) imaging, and multimodal imaging.

A biotechnological perspective on the application of iron oxide magnetic colloids modified with polysaccharides

Iron oxide magnetic nanoparticles (MNPs) alone are suitable for a broad spectrum of applications, but the low stability and heterogeneous size distribution in aqueous medium represent major setbacks. These setbacks can however be reduced or diminished through the coating of MNPs with various polymers, especially biopolymers such as polysaccharides. Polysaccharides are biocompatible, non-toxic and renewable; in addition, they possess chemical groups that permit further functionalization of the MNPs. Multifunctional entities can be created through decoration with specific molecules e.g. proteins, peptides, drugs, antibodies, biomimetic ligands, transfection agents, cells, and other ligands. This development opens a whole range of applications for iron oxide nanoparticles. In this review the properties of magnetic structures composed of MNPs and several polysaccharides (Agarose, Alginate, Carrageenan, Chitosan, Dextran, Heparin, Gum Arabic, Pullulan and Starch) will be discussed, in view of their recent and future biomedical and biotechnological applications.