Chemical Proteomics and Morphological Profiling Revealing MYDGF as a Target for Synthetic Anticancer Macromolecules

Biodegradable guanidinium-functionalized polycarbonates kill cancer cells via membrane translocation without causing resistance after repeated use, but the exact molecular targets of the polycarbonates are unknown. Here, we investigate the protein targets of the polycarbonates through affinity-based protein profiling and report myeloid-derived growth factor (MYDGF) as the main protein target. Direct binding of the polycarbonates to MYDGF protein is validated through biolayer interferometry. MYDGF is overexpressed in a range of cancer cells, and knockdown of MYDGF is shown to reduce cell proliferation in cancer cells. Through morphological profiling, we also identify similarities in phenotypic effects of the functionalized polycarbonates with topoisomerase I inhibitors, MDM2 inhibitors, and phosphatidylinositol 3kinase inhibitors against cancer cells, suggesting a common mechanism through the PIK3/AKT pathway leading to apoptosis. These findings present the first macromolecular compound targeting MYDGF and may serve as an example for MYDGF modulation as a potential new target for macromolecular chemotherapeutic development.

Pectic polysaccharides from Biluochun Tea: A comparative study in macromolecular characteristics, fine structures and radical scavenging activities in vitro

In this study, two acidic Biluochun Tea polysaccharides (BTP-A₁₁ and BTP-A₁₂) were investigated comparatively, which mainly consisted of Rha, Ara, Gal and GalA, possibly suggesting their pectic nature. Structurally, their galacturonan backbones composed of →4)-α-D-GalpA-(1→ and →2)-α-L-Rhap-(1→ were revealed similar, while Ara- and Gal-based branches attached to the O-2 of →2)-α-L-Rhap-(1→ were in distinctive types, proportions, extensibilities and branching degrees. This could lead to their different macromolecular characteristics, where BTP-A₁₁ with higher M_w presented a more hyper-branched chain conformation and relatively higher structural flexibility/compactness, thereby resulting in a lower exclusion effect and an insufficient hydrodynamic volume. Besides, better radical scavenging activities in vitro were also determined for Gal-enriched BTP-A₁₁, where a larger surface area containing more H-donating groups were related to its higher M_w, more hyper-branched conformation, lower DM and higher DA. Therefore, the understanding of structure-property-activity relationships was improved to some degrees for acidic Biluochun Tea polysaccharides, which could be potentially required for more applications in food, medical and cosmetic fields.

Characterization and diabetic wound healing benefits of protein-polysaccharide complexes isolated from an animal ethno-medicine Periplaneta americana L

Periplaneta americana L. (PA), a type of animal medicine, has been widely used for wound healing in clinical settings. In order to further investigate the bioactive wound healing substances in PA, crude PA protein-polysaccharide complexes were further purified by cellulose DE-52 and Sephadex G100 chromatography in succession. Among these isolated fractions, two fractions eluted by 0.3 M and 0.5 M NaCl with the higher yield, respectively named PaPPc2 and PaPPc3 respectively, were chosen for the wound healing experiments. Mediated by HPGPC, amino acid and monosaccharide composition analysis, circular dichroism spectrum, glycosylation type, FT-IR, and ¹H NMR analysis, the characterization of PaPPc2 and PaPPc3 was implemented. And then, the benefits of PaPPcs to promote cell proliferation, migration, and tube formation of HUVECs were determined in vitro, indicated these fractions would facilitate angiogenesis. Finally, as proof of concept, PaPPc2 and PaPPc3 were employed to accelerate the acute wounds of diabetic mice, involving in increase blood vessels and the amounts of angiogenesis-related cytokines (α-SMA, VEGF, and CD31). In short, this study provides an experimental basis to demonstrate the protein-polysaccharide complexes of Periplaneta americana L. as its wound healing bioactive substances.

Functional Macromolecular Adhesives for Bone Fracture Healing

Compared with traditional internal fixation devices, bone adhesives are expected to exhibit remarkable advantages, such as improved fixation of comminuted fractures and maintained spatial location of fractured scattered bone pieces in treating bone injuries. In this review, different bone adhesives are summarized from the aspects of bone tissue engineering, and the applications of bone adhesives are emphasized. The concepts of "liquid scaffold" and "liquid plate" are proposed to summarize two different research directions of bone adhesives. Furthermore, significant advances of bone adhesives in recent years in mechanical strength, osseointegration, osteoconductivity, and osteoinductivity are discussed. We conclude this topic by providing perspectives on the state-of-the-art research progress and future development trends of bone adhesives. We hope this review will provide a comprehensive summary of bone adhesives and inspire more extensive and in-depth research on this subject.

Detoxification of the Toxic Sulfur Mustard Simulant by a Supramolecular Antidote in Vitro and in Vivo

Although great potential hazards and threats still occur from sulfur mustard, there are no specific medicine or therapy for the intoxication of sulfur mustard. Herein, we have demonstrated a supramolecular approach for the detoxification of the sulfur mustard simulant CEES (4) in vitro and in vivo by carboxylatopillar[5]arene potassium salts (CP[5]AK 1) efficiently based on host-guest interactions. The encapsulation of CEES (4) by the cavity of the pillar[5]arene 2 is driven by C-H···π interactions between CEES (4) and the electron-rich cavity of pillar[5]arene 2, which was investigated by 1H NMR titration, density functional theory studies, and the independent gradient model studies. CEES (4) is degradated to the reactive sulfonium salts quickly in aqueous media, resulting in the alkylation of DNA and proteins. The sulfonium salts can be encapsulated by CP[5]AK 1 efficiently, which accelerates the degradation of the sulfonium salts about 14 times. The cell and animal experiments indicated that the bioactivities of the sulfonium salts are inhibited with the formation of stable host-guest complexes, and CP[5]AK 1 has a good therapeutic effect on the damages caused by CEES (4) at either pre- or post-treatments. Due to the low cytotoxicity and good therapeutic effect, the anionic pillar[5]arenes are expected to be developed as specific antidotes against sulfur mustard (HD).

Pillar[6]arene-Based Supramolecular Nanocatalysts for Synergistically Enhanced Chemodynamic Therapy by the Intracellular Cascade Reaction

Chemodynamic therapy (CDT) based on the intracellular Fenton reaction has become increasingly explored in cancer treatment. However, the mildly acidic tumor microenvironment and the limited amount of intracellular hydrogen peroxide (H₂O₂) will create issues for CDT to perform a sustained and high-efficiency treatment. Therefore, how to selectively reduce the pH value and augment the amount of H₂O₂ in tumor tissues has become the key factor for realizing excellent CDT. Besides, the majority of the reported CDT systems have been constructed from iron-based inorganic or metal-organic framework nanomaterials due to the decisive role of metals in CDT, which restricts the development of CDT. In this study, inspired by the host-guest interactions between pillar[6]arene and ferrocene, a ternary pillar[6]arene-based supramolecular nanocatalyst (GOx@T-NPs) for CDT is reported for the first time. GOx@T-NPs not only exhibited a high-efficiency catalytic ability to convert glucose into hydroxyl radicals (^•OH) and to reduce the pH value inside cancer cells for significant enhancement of the CDT effect, but they also showed sensitive glutathione-induced camptothecin (CPT) prodrug release capacity for further improving the efficiency of CDT. Hence, GOx@NPs possessed excellent ability to synergistically enhance the CDT. Additionally, an antitumor mechanism study showed that the prominent tumor inhibition capacity of GOx@T-NPs was derived from trimodal synergistic interactions of CDT, starvation therapy, and chemotherapy. Moreover, GOx@T-NPs manifested good biocompatibility and tumor selectivity with few side effects in major organs. This work broadens the range of materials available for CDT and demonstrates new developments in pillar[n]arene-based multimodal synergistic treatment systems.

Supramolecular Drug Delivery System from Macrocycle-Based Self-Assembled Amphiphiles for Effective Tumor Therapy

Intelligent drug delivery systems (DDSs) that can improve therapeutic outcomes of antitumor agents and decrease their side effects are urgently needed to satisfy special requirements of treatment of malignant tumors in clinics. Here, the fabrication of supramolecular self-assembled amphiphiles based on the host-guest recognition between a cationic water-soluble pillar[6]arene (WP6A) host and a sodium decanesulfonate guest (G) is reported. The chemotherapeutic agent doxorubicin hydrochloride (DOX) can be encapsulated into the formed vesicle (G/WP6A) to construct supramolecular DDS (DOX@G/WP6A). WP6A affords strong affinities to G to avoid undesirable off-target leakage during delivery. Nanoscaled DOX@G/WP6A is capable of preferentially accumulating in tumor tissue via enhanced permeability and retention (EPR) effect. After internalization by tumor cells, the abundant adenosine triphosphate (ATP) binds competitively with WP6A to trigger the disintegration of self-assembled vesicles with the ensuing release of DOX. In vitro and in vivo research confirmed that DOX@G/WP6A is not only able to promote antitumor efficacy but also reduce DOX-related systemic toxicity. The above favorable findings are ascribed to the formation of ternary self-assembly, which profits from the combination of the factors of the EPR effect and the ATP-triggered release.

Injectable Magnetic-Responsive Short-Peptide Supramolecular Hydrogels: Ex Vivo and In Vivo Evaluation

The inclusion of magnetic nanoparticles (MNP) in a hydrogel matrix to produce magnetic hydrogels has broadened the scope of these materials in biomedical research. Embedded MNP offer the possibility to modulate the physical properties of the hydrogel remotely and on demand by applying an external magnetic field. Moreover, they enable permanent changes in the mechanical properties of the hydrogel, as well as alterations in the micro- and macroporosity of its three-dimensional (3D) structure, with the associated potential to induce anisotropy. In this work, the behavior of biocompatible and biodegradable hydrogels made with Fmoc-diphenylalanine (Fmoc-FF) (Fmoc = fluorenylmethoxycarbonyl) and Fmoc-arginine-glycine-aspartic acid (Fmoc-RGD) short peptides to which MNP were incorporated was studied in detail with physicochemical, mechanical, and biological methods. The resulting hybrid hydrogels showed enhance mechanical properties and withstood injection without phase disruption. In mice, the hydrogels showed faster and improved self-healing properties compared to their nonmagnetic counterparts. Thanks to these superior physical properties and stability during culture, they can be used as 3D scaffolds for cell growth. Additionally, magnetic short-peptide hydrogels showed good biocompatibility and the absence of toxicity, which together with their enhanced mechanical stability and excellent injectability make them ideal biomaterials for in vivo biomedical applications with minimally invasive surgery. This study presents a new approach to improving the physical and mechanical properties of supramolecular hydrogels by incorporating MNP, which confer structural reinforcement and stability, remote actuation by magnetic fields, and better injectability. Our approach is a potential catalyst for expanding the biomedical applications of supramolecular short-peptide hydrogels.

Nano Milk Protein-Mucilage Complexes: Characterization and Anticancer Effect

The anticancer activity of natural compounds has recently attracted multidisciplinary research. In this study, the complexation of milk proteins (MP) with Isabgol husk mucilage (IHM) and Ziziphus spina-christi mucilage (NabM) was investigated. In this context, the physicochemical properties of milk protein mucilage complexes (MPMC) including pH, Carr's index, water solubility, and water absorption indices were measured, and the flow behavior was studied. In addition, the amino acid profile, protein digestibility, and phenolic and flavonoids content of MPMC were explored, and the microstructure of the complexes was visualized using transmission electron microscopy. The antioxidant and anticancer potencies of MPMC against two cancerous cell lines, human liver cancer HEPG-2 and breast cancer MCF-7, in comparison with two normal cell lines, namely, Bj-1 and MCF-12F, were tested using neutral red uptake assay. The results revealed that MPMC had scavenging activity against DPPH, ABTS, and HS radicals. Moreover, MPMC has the potential to prevent DNA damage induced by oxidative stress in Type-Fenton's reaction. The results of the neutral red assay showed significant growth inhibition of both HEPG-2, MCF-7, whereas no significant cytotoxic effect was detected against Bj-1 and MCF-12F. RT-qPCR results indicated MPMC stimulated apoptosis as revealed by the upregulation of the pro-apoptosis gene markers Casepase-3, p53, Bax. Meanwhile, the anti-apoptosis Bcl-2 gene was downregulated. However, no significant difference was observed in normal cell lines treated with MPMC. In conclusion, MPMC can be considered as a promising anticancer entity that can be used in the development of novel cancer therapeutics with comparable activity and minimal side effects compared to conventional cancer chemotherapies.

Supramolecular Cylinders Target Bulge Structures in the 5' UTR of the RNA Genome of SARS-CoV-2 and Inhibit Viral Replication*

The untranslated regions (UTRs) of viral genomes contain a variety of conserved yet dynamic structures crucial for viral replication, providing drug targets for the development of broad spectrum anti-virals. We combine in vitro RNA analysis with molecular dynamics simulations to build the first 3D models of the structure and dynamics of key regions of the 5' UTR of the SARS-CoV-2 genome. Furthermore, we determine the binding of metallo-supramolecular helicates (cylinders) to this RNA structure. These nano-size agents are uniquely able to thread through RNA junctions and we identify their binding to a 3-base bulge and the central cross 4-way junction located in stem loop 5. Finally, we show these RNA-binding cylinders suppress SARS-CoV-2 replication, highlighting their potential as novel anti-viral agents.

Optimization of intracellular macromolecule delivery by nanoparticle-mediated photoporation

Nanoparticle-mediated photoporation is a novel delivery platform for intracellular molecule delivery. We studied the dependence of macromolecular delivery on molecular weight and sought to enhance delivery efficiency. DU145 prostate cancer cells were exposed to pulsed laser beam in the presence of carbon-black nanoparticles. Intracellular uptake of molecules decreased with increasing molecular weight. Attributing this dependence to molecular diffusivity, we hypothesized that macromolecular delivery efficiency could be enhanced by increasing either laser fluence or laser exposure duration at low fluence. We observed increased percentages of macromolecule uptake by cells in both cases. However, trade-off between cell uptake and viability loss was most favorable at low laser fluence (25-29 mJ/cm²) and longer exposure durations (4-5 min). We conclude that long exposure at low laser fluence optimizes intracellular macromolecule delivery by nanoparticle-mediated photoporation, which may be explained by longer time for macromolecules to diffuse into cells, during and between laser pulses.

Synthesis and Anticancer Activity of Triazole Linked Macrocycles and Heterocycles

Synthesis of macrocylic enones starting from alkyl ether and triazole as a linker was achieved using click reaction and intramolecular aldol condensation. The newly synthesized macrocyclic enone was successfully utilized as a dipolarophile in 1,3-dipolar cycloaddition. The dipoles generated from hydrazine hydrochloride, hydroxylamine and guanidine hydrochloride were reacted with macrocyclic enone to give a new class of spiro aminopyrimidines, phenyl pyrazoles and isoxazoles grafted macrocycles in good yield. The structures of newly synthesized compounds were confirmed with IR, NMR and mass spectroscopy and evaluated for their anti cancer activity.

Supramolecular Bait to Trigger Non-Equilibrium Co-Assembly and Clearance of Aβ42

In living systems, non-equilibrium states that control the assembly-disassembly of cellular components underlie the gradual complexification of life, whereas in nonliving systems, most molecules follow the laws of thermodynamic equilibrium to sustain dynamic consistency. Little is known about the roles of non-equilibrium states of interactions between supramolecules in living systems. Here, a non-equilibrium state of interaction between supramolecular lipopolysaccharide (LPS) and Aβ42, an aggregate-prone protein that causes Alzheimer's disease (AD), was identified. Structurally, Aβ42 presents a specific groove that is recognized by the amphiphilicity of LPS bait in a non-equilibrium manner. Functionally, the transient complex elicits a cellular response to clear extracellular Aβ42 deposits in neuronal cells. Since the impaired clearance of toxic Aβ42 deposits correlates with AD pathology, the non-equilibrium LPS and Aβ42 could represent a useful target for developing AD therapeutics.

Thermally Stable and Antimicrobial Active Poly(Catechin) Obtained by Reaction with a Cross-Linking Agent

(+)-Catechin is a flavonoid with valuable antioxidant and antimicrobial properties, found in significant amounts in green tea leaves. Polymeric forms of catechin have been obtained by enzymatic reaction, photopolymerization, and polycondensation in designed processes. However, so far, poly(catechin) has not been received in the cross-linking reaction. Reactions with the cross-linking compound allowed for the preparation of antibacterial and antioxidant materials based on quercetin and rutin. The aim of the research was to obtain, for the first time, poly(catechin) by reaction with glycerol diglycide ether cross-linking compound. The polymeric form of (+)-catechin was confirmed using FTIR and UV-Vis spectroscopy. In addition, thermal analysis (TG and DSC) of the polymeric catechin was performed. The antioxidant and antibacterial activity of poly (flavonoid) was also analyzed. Poly(catechin) was characterized by greater resistance to oxidation, better thermal stability and the ability to reduce transition metal ions than (+)-catechin. In addition, the polymeric catechin had an antimicrobial activity against Staphylococcus aureus stronger than the monomer, and an antifungal activity against Aspergillus niger comparable to that of (+)-catechin. The material made on the basis of (+)-catechin can potentially be used as a pro-ecological stabilizer and functional additive, e.g., for polymeric materials as well as dressing materials in medicine.

Naphthalimide Imidazolium-Based Supramolecular Hydrogels as Bioimaging and Theranostic Soft Materials

1,8-Naphthalimide-based imidazolium salts differing for the alkyl chain length and the nature of the anion were synthesized and characterized to obtain fluorescent probes for bioimaging applications. First, their self-assembly behavior and gelling ability were investigated in water and water/dimethyl sulfoxide binary mixtures. Only salts having longer alkyl chains were able to give supramolecular hydrogels, whose properties were investigated by using a combined approach of fluorescence, resonance light scattering, and rheology measurements. Morphological information was obtained by scanning electron microscopy. In addition, conductive properties of organic salts in solution and gel state were analyzed. Imidazolium salts were successfully tested for their possible application as bioimaging and cytotoxic agents toward three cancer cell lines and a nontumoral epithelial cell line. Characterization of their behavior was performed by MTT and cell-based assays. Finally, the biological activity of hydrogels was also investigated. Collectively, our findings showed that naphthalimide-based imidazolium salts are promising theranostic agents and they were able to preserve their biological properties also in the gel phase.

Immune-enhancing effects of anionic macromolecules extracted from Codium fragile coupled with arachidonic acid in RAW264.7 cells

Arachidonic acid (ARA) is an integral constituent of the biological cell membrane, conferring it with fluidity and flexibility, which are necessary for the function of all cells, especially nervous system, skeletal muscle, and immune system. Codium species biosynthesize sulfated polysaccharides with very distinct structural features. Some of them have different biological activities with great potential in pharmaceutical applications. In this study, anionic macromolecules extracted from Codium fragile were investigated for their cooperative immune-enhancing activities with ARA. The cooperation between ARA and Codium resulted in increased, dose-dependent nitric oxide production and iNOS gene expression. In addition, co-treatment of ARA and Codium effectively increased pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), compared with Codium alone. We also demonstrated that the expression of COX-2 mRNA was also increased, which is responsible for the production of inflammatory mediator prostaglandins and their metabolites. Compared to the Codium group, the co-treatment of Codium with ARA enhanced the phosphorylation of nuclear factor-κB p-65, p38, and extracellular signal-related kinase 1/2, indicating that this combination stimulated immune response through nuclear factor-κB and mitogen-activated protein kinase pathways. These results indicated that the coordination of arachidonic acid with polysaccharide extracted from seaweed may be a potential source of immunomodulatory molecules.

Pillar[5]arene-Based Switched Supramolecular Photosensitizer for Self-Amplified and pH-Activated Photodynamic Therapy

Photodynamic therapy (PDT) has emerged as a promising and spatiotemporally controllable cancer treatment modality. However, serious skin photosensitization during the PDT process limits the clinical application of PDT. Thus, the construction of "smart" and multifunctional photosensitizers has attracted substantial interest. Herein, we develop a mitochondria-targeting and pH-switched hybrid supramolecular photosensitizer by the host-guest interaction. The PDT efficacy of supramolecular photosensitizers can be quenched by the Förster resonance energy transfer (FRET) effect during long circulation and activated by the dissociation of supramolecular photosensitizers in an acidic tumor microenvironment, benefitting from the dynamic feature of the host-guest interaction and pH responsiveness of the water-soluble pillar[5]arene on gold nanoparticles. The rational integration of mitochondria-targeting and reductive glutathione (GSH) elimination in the hybrid switchable supramolecular photosensitizer prolongs the lifetime of reactive oxygen species generated in the PDT near mitochondria and further amplifies the PDT efficacy. Thus, the facile and versatile construction of switchable supramolecular photosensitizer offers not only the targeted and precise phototherapy but also high therapeutic efficacy, which would provide a new path for the clinic application of PDT.

Smart Microenvironment-Responsive Organocopper(II) Supramolecular Polymers to Regulate the Stability and Anticancer Efficacy by Different Substituents

The search for chemotherapeutic drugs with a high efficiency and low toxicity continues to be a challenge in tumor treatment for scientists. Organometallic supramolecular polymers are an attractive option to achieve this goal, not only due to the fact that they possess both advantages of metal complexes and nanostructures but also because they are usually sensitive to pH. Here, we report the design and synthesis of a series novel smart microenvironment-responsive organocopper(II) supramolecular polymers with various substituted ligands to regulate their stability and anticancer efficacy. The investigation of the possible mechanisms revealed that the organocopper(II) polymers enter cancer cells through endocytosis and then induce apoptosis of cancer cells. Furthermore, the in vivo anticancer efficacy study demonstrated that these organocopper(II) polymers inhibited the tumor growth effectively without damage to the major organs. Overall, the organocopper(II) supramolecular polymers present a promising pathway to achieve high-efficiency and low-toxicity chemotherapy.

Linear Alternating Supramolecular Photosensitizer for Enhanced Photodynamic Therapy

Supramolecular polymers with facile and versatile architectures via noncovalent connection present great potential in biological fields. Herein, a linear alternating supramolecular polymer is constructed via host-guest inclusion interaction between cyclodextrin dimer (CD₂) and bifunctional adamantane-conjugated porphyrin (TPP-Ad₂). The supramolecular alternating structure of CD/TPP could not only suppress the aggregation of PSs to improve the photophysical properties because of the steric hindrance but also enhance the water solubility of PSs induced from cyclodextrin moieties. The nanoplatform obtained by this linear alternating supramolecular polymer (TPP-Ad₂/CD₂) presents significantly enhanced photodynamic therapy (PDT) efficacy, providing a promising path for PDT.

Post-Thaw Culture and Measurement of Total Cell Recovery Is Crucial in the Evaluation of New Macromolecular Cryoprotectants

The storage and transport of cells is a fundamental technology which underpins cell biology, biomaterials research, and emerging cell-based therapies. Inspired by antifreeze and ice-binding proteins in extremophiles, macromolecular (polymer) cryoprotectants are emerging as exciting biomaterials to enable the reduction and/or replacement of conventional cryoprotective agents such as DMSO. Here, we critically study post-thaw cellular outcomes upon addition of macromolecular cryoprotectants to provide unambiguous evidence that post-thaw culturing time and a mixture of assays are essential to claim a positive outcome. In particular, we observe that only measuring the viability of recovered cells gives false positives, even with non-cryoprotective polymers. Several systems gave apparently high viability but very low total cell recovery, which could be reported as a success but in practical applications would not be useful. Post-thaw culture time is also shown to be crucial to enable apoptosis to set in. Using this approach we demonstrate that polyampholytes (a rapidly emerging class of cryoprotectants) improve post-thaw outcomes across both measures, compared to poly(ethylene glycol), which can give false positives when only viability and short post-thaw time scales are considered. This work will help guide the discovery of new macromolecular cryoprotectants and ensure materials which only give positive results under limited outcomes can be quickly identified and removed.

General dual functionalisation of biomacromolecules via a cysteine bridging strategy

Site-selective modification of peptides and proteins has resulted in the development of a host of novel tools for the study of cellular systems or the synthesis of enhanced biotherapeutics. There is a need for useful methodologies that enable site-selective modification of native peptides or proteins, which is even more prevalent when modification of the biomolecule with multiple payloads is desired. Herein, we report the development of a novel dual functional divinylpyrimidine (dfDVP) platform that enables robust and modular modification of peptides, antibody fragments and antibodies. These biomacromolecules could be easily functionalised with a range of functional payloads (e.g. fluorescent dyes, cytotoxic warheads or cell-penetrating tags). Importantly, the dual functionalised peptides and antibodies demonstrated exquisite bioactivity in a range of in vitro cellular assays, showcasing the enhanced utility of these bioactive conjugates.

Biologically active macromolecules: Extraction strategies, therapeutic potential and biomedical perspective

Marine biome exhibits an immense essence of excellence and enriched with high-value bioactive compounds of therapeutic and biomedical value. During the past several years, an array of biologically active molecules has been extracted/isolated and purified from numerous sources of marine origin with the aid of distinct techniques and methodologies for newer applications. The growing demand for bioactive molecules with unique functionalities in various industrial divisions, such as therapeutic sectors and biomedical, has endorsed the necessity for highly suitable and standardized strategies to extract these bioactive components using a state-of-the-art and inexpensive measures. This is also because many in practice conventional extraction methodologies suffer from processing limitations and low-yield issues. Besides that, other major issues include (i) decrease efficacy, (ii) excessive energy cost, (iii) low yield, (iv) lower cost-effective ratio, (v) minimal selectivity, (vi) low activity, and (vii) stability, etc. In this context, there is an urgent need for new and robust extraction strategies. The synergies of modern extraction techniques with efficient and novel pretreatment approaches, such as the integration of enzymes, accompanied by conventional extraction processes, should be the utmost goal of current research and development studies. The typical effectivity of the extraction techniques mostly relies on these points, i.e., (i) know-how about the source nature and type, (ii) understanding the structural and compositional profile, (iii) influence of the processing factors, (iv) interplay between the extraction conditions and the end-product, (v) understanding the available functional entities, (vi) reaction chemistry of the extract bioactive compounds, and (vii) effective exploitation of the end-product in the marketplace. Marine biome, among numerous naturally occurring sources, has been appeared an immense essence of excellence to isolate an array of biologically active constituents with medicinal values and related point-of-care applications. Herein, we reviewed the salient information covering various therapeutic potential and biomedical perspectives. Following a brief introduction and marine pharmacognosy, an array of high-value biomolecules of marine origin are discussed with suitable examples. From the robust extraction strategies viewpoint, a part of the review focuses on three techniques, i.e., (1) enzyme-assisted extraction (EAE), (2) supercritical-fluid extraction (SFE), and (3) microwave-assisted extraction (MAE). Each technique is further enriched with processing and workflow environment. The later part of the review is mainly focused on the therapeutic and biomedical perspectives of under-reviewed bio-active compounds or biomolecules. The previous and latest research on the anticancer, skin curative, cardio-protective, immunomodulatory and UV-protectant potentialities of marine-derived biologically active entities have been summarized with suitable examples and related pathways illustrations. Finally, the work is wrapped-up with current research challenges, future aspects, and concluding remarks.

Structure-Dependent Antibacterial Activity of Amino Acid-Based Supramolecular Hydrogels

Bacterial infections are currently a major concern to human health. Amino acid-based supramolecular polymer hydrogels, which boast intrinsic antibacterial activity, are an important solution due to their good biocompatibility, cost effectiveness, and tunable structural properties. Herein, we reported three types of transparent supramolecular hydrogel with intrinsic antibacterial activity from self-assembly of commercially available Fmoc-tryptophan (Fmoc-W), Fmoc-methionine (Fmoc-M), and Fmoc-tyrosine (Fmoc-Y). The resulting hydrogels selectively inhibited the growth of Gram-positive bacteria. Moreover, the order of antibacterial activity was Fmoc-W hydrogel > Fmoc-M hydrogel > Fmoc-Y hydrogel. The critical aggregation concentration (CAC) values were found at concentrations of approximately 0.0293, 0.1172, and 0.4688 mM for Fmoc-W, Fmoc-M, and Fmoc-Y, respectively. Transmission electron microscope (TEM) images revealed rigid and aligned nanofibers for Fmoc-W hydrogel, while flexible nanofibers for Fmoc-M hydrogel and Fmoc-Y hydrogel. The results indicated that stronger aggregation capability of the gelator and the synergistic nanostructural morphology with more rigid and aligned nanofibers can lead to higher antibacterial activity of its corresponding hydrogel. In addition, the molecular arrangements of Fmoc-amino acids in the hydrogels may also contribute to their antibacterial activity. These results can guide the rational design, fabrication, and future application of other self-assembled amino acid-based hydrogels with excellent antibacterial activity.

Diversiform and Transformable Glyco-Nanostructures Constructed from Amphiphilic Supramolecular Metallocarbohydrates through Hierarchical Self-Assembly: The Balance between Metallacycles and Saccharides

During the past decade, self-assembly of saccharide-containing amphiphilic molecules toward bioinspired functional glycomaterials has attracted continuous attention due to their various applications in fundamental and practical areas. However, it still remains a great challenge to prepare hierarchical glycoassemblies with controllable and diversiform structures because of the complexity of saccharide structures and carbohydrate-carbohydrate interactions. Herein, through hierarchical self-assembly of modulated amphiphilic supramolecular metallocarbohydrates, we successfully prepared various well-defined glyco-nanostructures in aqueous solution, including vesicles, solid spheres, and opened vesicles depending on the molecular structures of metallocarbohydrates. More attractively, these glyco-nanostructures can further transform into other morphological structures in aqueous solutions such as worm-like micelles, tubules, and even tupanvirus-like vesicles (TVVs). It is worth mentioning that distinctive anisotropic structures including the opened vesicles (OVs) and TVVs were rarely reported in glycobased nano-objects. This intriguing diversity was mainly controlled by the subtle structural trade-off of the two major components of the amphiphiles, i.e., the saccharides and metallacycles. To further understand this precise structural control, molecular simulations provided deep physical insights on the morphology evolution and balancing of the contributions from saccharides and metallacycles. Moreover, the multivalency of glyco-nanostructures with different shapes and sizes was demonstrated by agglutination with a diversity of sugar-binding protein receptors such as the plant lectins Concanavalin A (ConA). This modular synthesis strategy provides access to systematic tuning of molecular structure and self-assembled architecture, which undoubtedly will broaden our horizons on the controllable fabrication of biomimetic glycomaterials such as biological membranes and supramolecular lectin inhibitors.

Fine-Tuning the Linear Release Rate of Paclitaxel-Bearing Supramolecular Filament Hydrogels through Molecular Engineering

One key design feature in the development of any local drug delivery system is the controlled release of therapeutic agents over a certain period of time. In this context, we report the characteristic feature of a supramolecular filament hydrogel system that enables a linear and sustainable drug release over the period of several months. Through covalent linkage with a short peptide sequence, we are able to convert an anticancer drug, paclitaxel (PTX), to a class of prodrug hydrogelators with varying critical gelation concentrations. These self-assembling PTX prodrugs associate into filamentous nanostructures in aqueous conditions and consequently percolate into a supramolecular filament network in the presence of appropriate counterions. The intriguing linear drug release profile is rooted in the supramolecular nature of the self-assembling filaments which maintain a constant monomer concentration at the gelation conditions. We found that molecular engineering of the prodrug design, such as varying the number of oppositely charged amino acids or through the incorporation of hydrophobic segments, allows for the fine-tuning of the PTX linear release rate. In cell studies, these PTX prodrugs can exert effective cytotoxicity against glioblastoma cell lines and also primary brain cancer cells derived from patients and show enhanced tumor penetration in a cancer spheroid model. We believe this drug-bearing hydrogel platform offers an exciting opportunity for the local treatment of human diseases.

Construction of β-cyclodextrin-based supramolecular hyperbranched polymers self-assemblies using AB2-type macromonomer and their application in the drug delivery field

Despite some efforts have been made in the research of supramolecular hyperbranched polymers (SHPs) self-assemblies, the study which has not been consideration to date is the influence of incoming stimuli-responsive polymer chain on their self-assembly property undergo outer stimuli. The introduction of stimuli-responsive segments which could maintain their hydrophilic property are expected to affect the self-assembly behaviour of SHPs and expand their further biomedical application. In this paper, AB₂-type macromolecular monomer, LA-(CD-PDMA)₂, which consisted one lithocholic acid (LA) and two β-cyclodextrin terminated poly(2-(dimethylamino)ethyl methacrylate) segments (CD-PDMA) was synthesized. LA-(CD-PDMA)₂ based SHP were obtained based on the host-guest inclusion interactions of CD/LA moietes and with PDMA as pH-responsive hydrophilic chains. As a control to study the influence of incoming PDMA chains, both LA-(CD-PDMA)₂ based SHPs-1 and LA-CD₂ based SHPs-2 self-assemblies were comparatively investiged through 2D ¹H NMR ROESY, transmission electron microscopy (TEM) and dynamic light scattering (DLS). The results suggested that except for the higher drug loading efficiency LA-(CD-PDMA)₂ based SHPs-1 pocessing, the release rates of SHPs-1 increased notably at pH 5.0 than that of pH 7.4 due to the repulsion and stretch of protonated PDMA chains while the release rates of SHPs-2 showed no obvious difference. Finally, basic cell experiments demonstrated that the SHPs based self-assemblies can be internalized into cancer cells, indicating their potential application in the drug delivery field.

Sample Delivery Media for Serial Crystallography

X-ray crystallographic methods can be used to visualize macromolecules at high resolution. This provides an understanding of molecular mechanisms and an insight into drug development and rational engineering of enzymes used in the industry. Although conventional synchrotron-based X-ray crystallography remains a powerful tool for understanding molecular function, it has experimental limitations, including radiation damage, cryogenic temperature, and static structural information. Serial femtosecond crystallography (SFX) using X-ray free electron laser (XFEL) and serial millisecond crystallography (SMX) using synchrotron X-ray have recently gained attention as research methods for visualizing macromolecules at room temperature without causing or reducing radiation damage, respectively. These techniques provide more biologically relevant structures than traditional X-ray crystallography at cryogenic temperatures using a single crystal. Serial femtosecond crystallography techniques visualize the dynamics of macromolecules through time-resolved experiments. In serial crystallography (SX), one of the most important aspects is the delivery of crystal samples efficiently, reliably, and continuously to an X-ray interaction point. A viscous delivery medium, such as a carrier matrix, dramatically reduces sample consumption, contributing to the success of SX experiments. This review discusses the preparation and criteria for the selection and development of a sample delivery medium and its application for SX.

Bioinspired Shear-Flow-Driven Layer-by-Layer in Situ Self-Assembly

Layer-by-layer (LbL) assembly is widely applied as a coating technique for the nanoscale control of architecture and related properties. However, its translational applications are limited by the time-consuming and laborious nature of the process. Inspired by the blood-clotting process, herein, we develop a shear-flow-driven LbL (SF-LbL) self-assembly approach that accelerates the adsorption rate of macromolecules by mechanically configuring the polymer chain via a coil-stretch transition, which effectively simplifies and speeds the diffusion-controlled assembly process. The structural characteristics and surface homogeneity of the SF-LbL films are improved, and diverse three-dimensional structures can be achieved. Functional SF-LbL-assembled surfaces for corneal modification are successfully fabricated, and the surface of wounded rat corneas and skin can be directly decorated in situ with SF-LbL nanofilms due to the advantages of this approach. Furthermore, in situ SF-LbL self-assembly has promise as a simple approach for the wound dressing for interventional therapeutics in the clinic, as illustrated by the successful in situ fabrication of drug-free layers consisting of chitosan and heparin on the dorsal skin of diabetic mice to rescue defective wound healing. This bioinspired self-assembly approach is expected to provide a robust and versatile platform with which to explore the surface engineering of nanofilms in science, engineering, and medicine.

Immune-enhancing effects of anionic macromolecules extracted from Codium fragile on cyclophosphamide-treated mice

Immune-regulation and homeostasis are critical in cancer therapy and immunomodulatory biomaterials have been used to decrease side effects of immunosuppressant drugs. Anionic macromolecules (CFAMs) were isolated from the seaweed Codium fragile, and its immune-enhancing biological activities were examined in CY-induced immunosuppressed mice. CFAMs improved the splenic lymphocyte proliferation, NK cell activity, and spleen index. The expression of immune-associated genes was highly upregulated in splenic lymphocytes, and gene expression was differently regulated according to mitogens such as T-cell (Con A) and B-cell (LPS) mitogens. Additionally, CFAMs boosted the proliferation, NO production, and phagocytosis of peritoneal macrophages. CFAMs also considerably stimulated immune-associated gene expression in peritoneal macrophages. Moreover, our results showed CFAMs mediated its immune-enhancing effects via the MAPK pathway. These suggested CFAMs can be used as a potent immunomodulatory material under immune-suppressive condition. Furthermore, CFAMs may also be used as a bio-functional and pharmaceutical material for improving human health and immunity.

Enhanced transfection of a macromolecular lignin-based DNA complex with low cellular toxicity

Cationic polymers remain attractive tools for non-viral gene transfer. The effectiveness of these vectors rely on the ability to deliver plasmid DNA (pDNA) into the nucleus of cells. While we have previously demonstrated the potential of Lignin-PGEA-PEGMA as a non-viral gene delivery vector, alterations of cellular phenotype and cytotoxicity were observed post transfection. The present study aims to explore transfection conditions for high efficiency and low toxicity of the Lignin-PGEA-PEGMA based gene delivery system. Cellular toxicity was significantly reduced by using the centrifugation protocol, which enables rapid deposition of DNA complexes. Replacement of media post centrifugation resulted in minimal exposure of cells to excess polymers, which were toxic to cells. At an optimized DNA amount (500-750 ng) and molar ratios of nitrogen (N) in polymer to phosphate (P) in pDNA (N/P = 30-40), with the use of a novel transfection enhancer that facilitates endosomal escape and nuclear trafficking, the efficiency of gene delivery was increased significantly 24 h post transfection. The present study demonstrated an appropriately optimized protocol that enabled the utility of a novel cationic polymer blend with a mixture of fusogenic lipids and a histone deacetylate inhibitor in non-viral transfection, thereby providing an attractive alternative to costly commercial gene carriers.

Macromolecular-clustered facial amphiphilic antimicrobials

Bacterial infections and antibiotic resistance, particularly by Gram-negative pathogens, have become a global healthcare crisis. We report the design of a class of cationic antimicrobial polymers that cluster local facial amphiphilicity from repeating units to enhance interactions with bacterial membranes without requiring a globally conformational arrangement associated with highly unfavorable entropic loss. This concept of macromolecular architectures is demonstrated with a series of multicyclic natural product-based cationic polymers. We have shown that cholic acid derivatives with three charged head groups are more potent and selective than lithocholic and deoxycholic counterparts, particularly against Gram-negative bacteria. This is ascribed to the formation of true facial amphiphilicity with hydrophilic ion groups oriented on one face and hydrophobic multicyclic hydrocarbon structures on the opposite face. Such local facial amphiphilicity is clustered via a flexible macromolecular backbone in a concerted way when in contact with bacterial membranes.

Supramolecularly Engineered Circular Bivalent Aptamer for Enhanced Functional Protein Delivery

Circular bivalent aptamers (cb-apt) comprise an emerging class of chemically engineered aptamers with substantially improved stability and molecular recognition ability. Its therapeutic application, however, is challenged by the lack of functional modules to control the interactions of cb-apt with therapeutics. We present the design of a β-cyclodextrin-modified cb-apt (cb-apt-βCD) and its supramolecular interaction with molecular therapeutics via host-guest chemistry for targeted intracellular delivery. The supramolecular ensemble exhibits high serum stability and enhanced intracellular delivery efficiency compared to a monomeric aptamer. The cb-apt-βCD ensemble delivers green fluorescent protein into targeted cells with efficiency as high as 80%, or cytotoxic saporin to efficiently inhibit tumor cell growth. The strategy of conjugating βCD to cb-apt, and subsequently modulating the supramolecular chemistry of cb-apt-βCD, provides a general platform to expand and diversify the function of aptamers, enabling new biological and therapeutic applications.

Host-guest complexes of imazalil with cucurbit[8]uril and β-cyclodextrin and their effect on plant pathogenic fungi

We report the control of imazalil (IMZ) antifungal activity utilizing its non-covalent assembly with β-cyclodextrins (β-CD) and cucurbit[8]uril (CB8) macrocycles, as well as its stimuli-responsive disassembly with cadaverine. The NMR results are consistent with inclusion of a single IMZ molecule inside the cavities of either CB8 from its aromatic site or β-CD from its aliphatic end. Efficient complex formation with both host molecules and controlled released upon the addition of cadaverine is supported by NMR measurements. The stimuli-responsiveness of the same host-guest assemblies with cadaverine was validated against seven economically important plant pathogenic fungi which cause agriculturally important plant diseases across the globe. While loading the drug into macrocycles cavities suppressed its activity, subsequent adding of cadaverine efficiently restored it up. The results in the present paper enable researchers working in the area of mycology and plant pathology to inhibit or reduce the fungal growth on demand in order to control these economically important plant pathogenic fungi.

Supramolecular catalysis and dynamic assemblies for medicine

In this review, supramolecular catalysis refers to the integration of the catalytic process with molecular self-assembly driven by noncovalent interactions, and dynamic assemblies are the assemblies that form and dissipate reversibly. Cells extensively employ supramolecular catalysis and dynamic assemblies for controlling their complex functions. The dynamic generation of supramolecular assemblies of small molecules has made considerable progress in the last decade, though the disassembly processes remain underexplored. Here, we discuss the regulation of dynamic assemblies via self-assembly and disassembly processes for therapeutics and diagnostics. We first briefly introduce the self-assembly and disassembly processes in the context of cells, which provide the rationale for designing approaches to control the assemblies. Then, we describe recent advances in designing and regulating the self-assembly and disassembly of small molecules, especially for molecular imaging and anticancer therapeutics. Finally, we provide a perspective on future directions of the research on supramolecular catalysis and dynamic assemblies for medicine.

Macromolecular agents with antimicrobial potentialities: A drive to combat antimicrobial resistance

In recent years, the antimicrobial resistance (AMR) or multidrug resistance (MDR) has become a serious health concern and major challenging issue, worldwide. After decades of negligence, the AMR has now captured global attention. The increasing number of antibiotic-resistant strains has threatened the achievements of science and medicine since it inactivates conventional antimicrobial therapeutics. Scientists are trying to respond to AMR/MDR threat by exploring innovative platforms and new therapeutic strategies to tackle infections from these resistant strains and bypass treatment limitations related to these pathologies. The present review focuses on the utilization of bio-inspired novel constructs and their potential applications as novel antimicrobial agents. The first part of the review describes plant-based biological macromolecules containing an immense variety of secondary metabolites, which could be potentially used as alternative strategies to combat antimicrobial resistance. The second part discusses the potential of metal-based macromolecules as effective antimicrobial platforms for preventing infections from resistant strains. The third part comprehensively elucidates how nanoparticles, in particular, metal-integrated nanoparticles can overcome this AMR or MDR issue. Towards the end, information is given with critical concluding remarks, gaps, and finally envisioned with future considerations.

pH-Responsive Peptide Supramolecular Hydrogels with Antibacterial Activity

Smart hydrogels have received increasing attention for many applications. Here, we synthesized a class of cationic peptide amphiphiles that can self-assemble into hydrogels by ring-opening polymerization (ROP) and post-modification strategy. The incorporation of cationic lysine residues suppresses the formation of fibril-like structure and further the gelation ability of the samples. Sodium alginate (SA) is used to enhance the rheology performance of the hydrogels. The hydrogels exhibit pH-dependent self-assembly and the gelation behavior that enables them to be ideal smart hydrogel systems for biomedical applications. Furthermore, the as-prepared hybrid peptide hydrogels show antibacterial activity.

One-Component Supramolecular Filament Hydrogels as Theranostic Label-Free Magnetic Resonance Imaging Agents

Gadolinium (Gd)-based compounds and materials are the most commonly used magnetic resonance imaging (MRI) contrast agents in the clinic; however, safety concerns associated with their toxicities in the free ionic form have promoted the development of new generations of metal-free contrast agents. Here we report a supramolecular strategy to convert an FDA-approved anticancer drug, Pemetrexed (Pem), to a molecular hydrogelator with inherent chemical exchange saturation transfer (CEST) MRI signals. The rationally designed drug-peptide conjugate can spontaneously associate into filamentous assemblies under physiological conditions and consequently form theranostic supramolecular hydrogels for injectable delivery. We demonstrated that the local delivery and distribution of Pem-peptide nanofiber hydrogels can be directly assessed using CEST MRI in a mouse glioma model. Our work lays out the foundation for the development of drug-constructed theranostic supramolecular materials with an inherent CEST MRI signal that enables noninvasive monitoring of their in vivo distribution and drug release.

Supramolecular Control over Split-Luciferase Complementation

Supramolecular split-enzyme complementation restores enzymatic activity and allows for on-off switching. Split-luciferase fragment pairs were provided with an N-terminal FGG sequence and screened for complementation through host-guest binding to cucurbit[8]uril (Q8). Split-luciferase heterocomplex formation was induced in a Q8 concentration dependent manner, resulting in a 20-fold upregulation of luciferase activity. Supramolecular split-luciferase complementation was fully reversible, as revealed by using two types of Q8 inhibitors. Competition studies with the weak-binding FGG peptide revealed a 300-fold enhanced stability for the formation of the ternary heterocomplex compared to binding of two of the same fragments to Q8. Stochiometric binding by the potent inhibitor memantine could be used for repeated cycling of luciferase activation and deactivation in conjunction with Q8, providing a versatile module for in vitro supramolecular signaling networks.

Functionalization of DNA-dendron supramolecular fibers and application in regulation of Escherichia coli association

Specific carbohydrate recognition in biology is a dynamic process. Thus, supramolecular multivalent scaffolds with dynamic features have been applied to mimic this process. Herein, we prepared DNA-dendron supramolecular fibers and synthesized carbohydrate-oligonucleotide conjugates (C18-mannose). Via DNA hybridization, the C18-mannose could be guided onto the fiber platform and form multiple mannose-functionalized fibers, which can be utilized to agglutinate E. coli because of high affinity among multivalent mannose ligands and receptors on E. coli. In addition, via chain exchange reaction of DNAs, the E. coli could be dissociated by replacing multivalent mannose ligands with competitive unmodified DNA sequences. The association and dissociation processes of E. coli are confirmed by fluorescent microscope and transmission electron microscope (TEM). These results not only demonstrate the ability of DNA-dendron fibers in reversibly associating E. coli but also illustrate their potential to be an easily modified multivalent supramolecular platform.

Comparative studies, synthesis, spectroscopic and characterization of N-methylisatin-3-Girard's T and P hydrazone complexes

Different types of complexes derived from the reactions of N-methylisatin Girard's T hydrazone, N,N,N-trimethyl-2-[(2z)-2-(1-methyl-2-oxo-1,2-dihydro-3H-indole-3-ylidene) hydrazino]-2-oxo-ethan ammonium chloride (MIGT) and N-methylisatin Girard's P hydrazone, 1-{2-(2z)-2-[(1-methyl-2-oxo-1,2-dihydro-3H-indole-3-ylidene) hydrazino]-2-oxoethyl}pyridinium chloride (MIGP) with Fe(3+), Al(3+), Sb(3+) and Sn(2+) salts were synthesized. The isolated complexes were characterized by elemental analyses, molar conductivities, spectral (IR, UV-Vis., (1)H NMR, mass), magnetic moments and thermal measurements. The values of conductance suggest that the complexes are conducting in polar solvents (EtOH, H2O and DMF). The IR spectra suggest that the ligands coordinate in a bidentate and/or tridentate manner via the carbonyl groups of both N-methylisatin and Girard's T and/or P and the (CN) group. The solvents inside and outside the coordination sphere were determined by weight loss and TGA methods. The octahedral geometry of the complexes is confirmed using spectral, magnetic and DFT method from DMOL(3) calculations. The ligands and their metal complexes were tested against different strains of bacteria and fungi.

Supramolecular assemblies of a conjugate of nucleobase, amino acids, and saccharide act as agonists for proliferation of embryonic stem cells and development of zygotes

The synthetic challenges in glycobiology and glycochemistry hamper the development of glycobiomaterials for biomedicine. Here we report the use of molecular self-assembly to sidestep the laborious synthesis of complex glycans for promoting the proliferation of murine embryonic stem (mES) cells. Our study shows that the supramolecular assemblies of a small molecule conjugate of nucleobase, amino acids, and saccharide, as a de novo glycoconjugate, promote the proliferation of mES cells and the development of zygotes into blastocysts of mouse. Molecular engineering confirms that each motif (i.e., adenine, Arg-Gly-Asp (RGD) domain, and glucosamine) is indispensable for the observed activity of the conjugate. As the first example of using assemblies of the molecular conjugates of multiple fundamental biological building blocks to control cell behaviors, this work illustrates an unprecedented approach to use supramolecular assemblies as multifunctional mimics of glycoconjugates.

A novel suspension formulation enhances intestinal absorption of macromolecules via transient and reversible transport mechanisms

PURPOSE

Medium chain fatty acid salts promote absorption by increasing paracellular permeability of the intestinal epithelium. Novel oily suspension (OS) formulation disperses a powder containing sodium caprylate and macromolecules such as octreotide or fluorescent dextran (FD). Formulation safety, macromolecule absorption and pharmacokinetic (PK)/pharmacodynamic (PD) were evaluated.

METHODS

Octreotide/OS toxicity was evaluated in monkeys following 9 months of daily oral enteric-coated capsule administration. The OS permeation effect was also assessed in rats, using FD/OS and octreotide/OS preparations. Octreotide/OS effects on circulating growth hormone (GH) levels were also measured.

RESULTS

Safety assessment of octreotide/OS in monkeys after 9 months showed minor drug-related findings, comparable to the injectable octreotide. Octreotide exposure levels were similar across the treatment periods. In rats, OS facilitated FD permeation up to 70 kDa in a reversible, spatial and dose-dependent manner, independent of the intestinal dosing site. Following OS administration, the staining pattern of the tight-junction protein, ZO-1, changed transiently, and a paracellular penetration marker, LC-biotin, permeated between adjacent epithelial cells. Enteral octreotide/OS absorption was dose-dependent and suppressed rat GH levels.

CONCLUSIONS

Oral octreotide/OS dosing was shown to be safe in monkeys. OS enhances intestinal absorption of active octreotide, likely by transient alteration of the tight junction protein complex.

Dephosphorylation of D-peptide derivatives to form biofunctional, supramolecular nanofibers/hydrogels and their potential applications for intracellular imaging and intratumoral chemotherapy

D-Peptides, as the enantiomers of the naturally occurring L-peptides, usually resist endogenous proteases and are presumably insensitive to most enzymes. But, it is unclear whether or how a phosphatase catalyzes the dephosphorylation from D-peptides. In this work, we examine the formation of the nanofibers of D-peptides via enzymatic dephosphorylation. By comparing the enzymatic hydrogelation of L-peptide and D-peptide based hydrogelators, we find that the chirality of the precursors of the hydrogelators affects little on the enzymatic hydrogelation resulted from the removal of the phosphate group from a tyrosine phosphate residue. The attachment of a therapeutic agent (e.g., taxol) or a fluorophore (e.g., 4-nitro-2,1,3-benzoxadiazole) to the D-peptide based hydrogelators affords a new type of biostable or biocompatible hydrogelators, which may find applications in intratumoral chemotherapy or intracellular imaging, respectively. This work, as the first comprehensive and systematic study of the unexpected enzymatic dephosphorylation of D-peptides, illustrates a useful approach to generate supramolecular hydrogels that have both biostability and other desired functions.

Cholesterol-peptide hybrids to form liposome-like vesicles for gene delivery

In this paper, four amphiphilic cholesterol-peptide conjugates (Ch-R5H5, Ch-R3H3, Ch-R5 and Ch-R5) were designed and synthesized, and their properties in gene delivery were evaluated in vitro with an aim of developing more efficient gene delivery carriers. These amphiphilic cholesterol-peptide conjugates are composed of hydrophobic cholesterol and positively charged peptides. They were able to self-assemble into micelles at low concentrations and their critical micelle concentrations in phosphate buffered saline (pH 7.4) are ≤85 µg/mL. Amphiphilic cholesterol-peptide conjugates condensed DNA more efficiently than a hydrophilic cationic oligoarginine (R10) peptide with no hydrophobic segment. Their transfection efficiencies were at least two orders of magnitude greater than that of R10 peptide in HEK-293 cells. Moreover, the introduction of histidine residues in cholesterol-peptide conjugates led to higher gene expression efficiency compared with cholesterol-peptides without histidine (Ch-R5 and Ch-R3), and the luciferase expression level was comparable or even higher than that induced by PEI at its optimal N/P ratio. In particular, Ch-R5H5 condensed DNA into smaller nanoparticles than Ch-R3H3 at higher N/P ratios, and the minimum size of Ch-R5H5/DNA complexes was 180 nm with zeta potential of 23 mV, achieved at the N/P ratio of 30. This liposome-like vesicle may be a promising gene delivery carrier for intravenous therapy.

Anti-UV activity of lignin-carbohydrate complex and related compounds

BACKGROUND

We recently reported that an alkaline extract of the leaves of Sasa senanensis Rehder (SE) and Lentinus edodes mycelia extract (LEM), exhibiting lignin-carbohydrate complex (LCC)-like activity, protected cells from UV-induced injury (referred to as anti-UV activity). We investigated whether LCC is the major active components responsible for anti-UV activity.

MATERIALS AND METHODS

Human oral squamous cell carcinoma HSC-2 cells were exposed to short UV irradiation in phosphate-buffered saline, containing different concentrations of LCC. After culturing for 48 h in fresh culture medium, the viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. From the dose-response curve, the 50% cytotoxic concentration (CC(50)) and the concentration that increased the viability of the UV-irradiated cells to 50% of the control value (EC(50)) were determined. The selectivity index (SI) was determined by the following equation: SI=CC(50)/EC(50).

RESULTS

LCCs (Fr. VI) of pine cones and seed shell, and sulfated LCC exhibited relatively high anti-UV activity (SI=7.1-38), compared with that of SE and LEM. LCCs with lower lignin content (Fr. VII) exhibited anti-UV activity, approximately one half that of Fr. VI. However, polysaccharides (laminarin, pullulan, dextran) introduced with dimethylaminoethyl- or sulfate groups with different substitution ratios were totally inactive (SI<1). The introduction of a sulfate group to LCC did not enhance the anti-UV activity of LCC. Sodium ascorbate and vanillin were the most active (SI=65), whereas gallic acid (SI=5), epigallocatechin gallate (SI=2.6), ar-trumeron (SI<1), and turmeric extract (SI<1) were much less active.

CONCLUSION

The prominent anti-UV activity of SE and LEM seems to be generated by LCCs present in the extract.

Multifunctional gadolinium-based dendritic macromolecules as liver targeting imaging probes

The quest for highly efficient and safe contrast agents has become the key factor for successful application of magnetic resonance imaging (MRI). The gadolinium (Gd) based dendritic macromolecules, with precise and tunable nanoscopic sizes, are excellent candidates as multivalent MRI probes. In this paper, a novel series of Gd-based multifunctional peptide dendritic probes (generation 2, 3, and 4) possessing highly controlled structures and single molecular weight were designed and prepared as liver MRI probes. These macromolecular Gd-ligand agents exhibited up to 3-fold increase in T(1) relaxivity comparing to Gd-DTPA complexes. No obvious in vitro cytotoxicity was observed from the measured concentrations. These dendritic probes were further functionalized with multiple galactosyl moieties and led to much higher cell uptake in vitro as demonstrated in T(1)-weighted scans. During in vivo animal studies, the probes provided better signal intensity (SI) enhancement in mouse liver, especially at 60 min post-injection, with the most efficient enhancement from the galactosyl moiety decorated third generation dendrimer. The imaging results were verified with analysis of Gd content in liver tissues. The design strategy of multifunctional Gd-ligand peptide dendritic macromolecules in this study may be used for developing other sensitive MRI probes with targeting capability.

Internalization of p53(14-29) peptide amphiphiles and subsequent endosomal disruption results in SJSA-1 cell death

In vivo peptide inhibition of tumor suppressor p53 binding to the protein MDM2 is hampered by inefficient delivery of the peptide. Our approach to couple a hydrophobic lipid-like tail on the inhibitory peptide p53(14-29) allowed its intracellular delivery in vitro, in a panel of different cell lines. The constructed chimeric molecules, termed peptide amphiphiles, further self-assembled into supramolecular structures, identified as elongated wormlike micelles. Internalization of peptides occurred following micelle disassembly, partly via clathrin-mediated endocytosis of monomers. Incubation of SJSA-1 cells in hypertonic culture media, aimed to disrupt endocytic vesicles, resulted in peptide amphiphile-mediated cell death. Our results provide the basis for the construction of novel therapeutic supramolecular nanoparticles and suggest hydrophobic modification of peptides as a promising strategy for enhancing delivery of impermeable peptides.

Synthesis, characterization, spectrophotometric, structural and antimicrobial studies of the newly charge transfer complex of p-phenylenediamine with π acceptor picric acid

Charge transfer complex (CTC) of donor, p-phenylenediamine (PPD) and acceptor, 2,4,6-trinitrophenol (picric acid) has been studied in methanol at room temperature. The CT complex was synthesized and characterized by elemental analysis, FTIR spectra, 1H NMR spectroscopy and electronic absorption spectra which indicate the CT interaction associated with proton migration from the acceptor to the donor followed by hydrogen bonding via N+-H⋯O-. The thermal stability of CT complex was studied using TGA and DTA analyses techniques. The CT complex was screened for its antifungal activity against Aspergillus niger (Laboratory isolate), Candida albicans (IQA-109) and Penicillium sp. (Laboratory isolate) and antibacterial activity against two Gram-positive bacteria Staphylococcus aureus (MSSA 22) and Bacillus subtilis (ATCC 6051) and two Gram-negative bacteria Escherichia coli (K 12) and Pseudomonas aeruginosa (MTCC 2488). It gives good antimicrobial activity. The stoichiometry of the CT complex was found to be 1:1. The physical parameters of CT complex were evaluated by the Benesi-Hildebrand equation. On the basis of the studies, the structure of CT complex is [(PPDH)+(PA)-], and a general mechanism for its formation is proposed.

Stratum corneum permeation and percutaneous drug delivery of hydrophilic molecules enhanced by cryopneumatic and photopneumatic technologies

Novel cryopneumatic technology (CPx) and photopneumatic technology (PPx) have been developed to enhance the permeation of the stratum corneum (SC) and percutaneous drug delivery (PDD). CPx produces micro-cracks at the skin surface by successively freezing and stretching the skin with vacuum suction. PPx combines stretching of the skin by vacuum suction with intense pulsed light. The enhancing effects of CPx and PPx were studied on ex vivo porcine skin and in vivo human skin models. Fluorescent hydrophilic macromolecules (FITC and FITC-Dextran) were used as drug surrogates. Fluorescent images of in vivo experiments show that the enhancing effect of CPx is due to drug permeation through the micro-cracks produced by freezing stretching cycles, while PPx could promote drug permeation through sweat glands. Both ex vivo and in vivo results strongly suggest that CPx and PPx can effectively enhance the permeation of the SC and PDD for the delivery of hydrophilic macromolecules.

Influence of biomacromolecules and humic acid on the aggregation kinetics of single-walled carbon nanotubes

The initial aggregation kinetics of single-walled carbon nanotubes (SWNTs) were studied using time-resolved dynamic light scattering. Aggregation of SWNTs was evaluated in the presence of natural organic matter [Suwannee River humic acid (SRHA)], polysaccharide (alginate), protein [bovine serum albumin (BSA)], and cell culture medium [Luria-Bertani (LB) broth] with varying solution concentrations of monovalent (NaCl) and divalent (CaCl(2)) salts. Increasing salt concentration and adding divalent calcium ions induced SWNT aggregation by screening electrostatic charge and thereby suppressing electrostatic repulsion, similar to observations with aquatic colloidal particles. The presence of biomacromolecules significantly retarded the SWNT aggregation rate. BSA protein molecules were most effective in reducing the rate of aggregation followed by SRHA, LB, and alginate. The slowing of the SWNT aggregation rate in the presence of the biomacromolecules and SRHA can be attributed to steric repulsion originating from the adsorbed macromolecular layer. The remarkably enhanced SWNT stability in the presence of BSA, compared to that with the other biomacromolecules and SRHA, is ascribed to the BSA globular molecular structure that enhances steric repulsion. The results have direct implications for the fate and behavior of SWNTs in aquatic environments and biological media.