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Type: Text × Subject: Hyaluronic acid ×

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    Magnetic Micromotors for Multiple Motile Sperm Cells Capture, Transport, and Enzymatic Release
    (Weinheim : Wiley-VCH Verlag, 2020) Xu, H.; Medina-Sánchez, M.; Schmidt, O.G.
    An integrated system combining a magnetically-driven micromotor and a synthetized protein-based hyaluronic acid (HA) microflake is presented for the in situ selection and transport of multiple motile sperm cells (ca. 50). The system appeals for targeted sperm delivery in the reproductive system to assist fertilization or to deliver drugs. The binding mechanism between the HA microflake and sperm relies on the interactions between HA and the corresponding sperm HA receptors. Once sperm are captured within the HA microflake, the assembly is trapped and transported by a magnetically-driven helical microcarrier. The trapping of the sperm-microflake occurs by a local vortex induced by the microcarrier during rotation-translation under a rotating magnetic field. After transport, the microflake is enzymatically hydrolyzed by local proteases, allowing sperm to escape and finally reach the target location. This cargo-delivery system represents a new concept to transport not only multiple motile sperm but also other actively moving biological cargoes.
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    Hyaluronan Graft Copolymers Bearing Fatty-Acid Residues as Self-Assembling Nanoparticles for Olanzapine Delivery
    (Basel : MDPI, 2019) Paolino, Marco; Licciardi, Mariano; Savoca, Cristina; Giammona, Gaetano; De Mohac, Laura Modica; Reale, Annalisa; Giuliani, Germano; Komber, Hartmut; Donati, Alessandro; Leone, Gemma; Magnani, Agnese; Anzini, Maurizio; Cappelli, Andrea
    In order to evaluate the potential of a technology platform based on hyaluronan copolymers grafted with propargylated ferulate fluorophores (HA-FA-Pg) in the development of drug delivery systems, the propargyl groups of HA-FA-Pg derivatives were employed with oleic acid (OA) or stearic acid (SA) residues across a biocompatible hexa(ethylene glycol) (HEG) spacer. The designed materials (i.e., HA-FA-HEG-OA or HA-FA-HEG-SA) showed clear-cut aggregation features in an aqueous environment, as confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM), generating nanoaggregate systems. In fact, HA-FA-HEG-OA and HA-FA-HEG-SA derivatives showed the property to create self-assembled cytocompatible nanostructured aggregates in water, thanks to the simultaneous presence of hydrophilic portions in the polymeric backbone, such as hyaluronic acid, and hydrophobic portions in the side chains. Furthermore, the designed materials interact with living cells showing a high degree of cytocompatibility. The potential ability of nanosystems to load pharmacologically active molecules was assessed by the physical entrapment of olanzapine into both polymeric systems. The drug loading evaluation demonstrated that the nanoparticles are able to incorporate a good quantity of olanzapine, as well as improve drug solubility, release profile, and cytocompatibility. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.
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    Cell-free protein synthesis and in situ immobilization of deGFP-MatB in polymer microgels for malonate-to-malonyl CoA conversion
    (Cambridge : RSC, 2020) Köhler, Tony; Heida, Thomas; Hoefgen, Sandra; Weigel, Niclas; Valiante, Vito; Thiele, Julian
    In the present work, microgels were utilized as a cell-free reaction environment to produce a functional malonyl-CoA synthetase (deGFP-MatB) under geometry-controlled transcription and translation. Our approach combines the straight-forward optimization of overall protein yield of an E. coli-based cell-free protein synthesis (CFPS) system based on concentration screening of magnesium and potassium glutamate, DNA as well as polyethylene glycol (PEG), and its innovative usage in microgel-based production of a key enzyme of the polyketide synthesis pathway. After partial modification of the carboxyl groups of hyaluronic acid (HA) with 5′-methylfuran groups via 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methyl-morpholinium chloride (DMTMM)-activation, these were further functionalized with dibenzocyclooctyne (DBCO) and nitrilotriacetic acid (NTA) groups by bio-orthogonal [4+2] Diels-Alder cycloaddition to yield a bifunctional macromer. After coupling the DBCO groups with azide-functionalized DNA, containing the genetic information for deGFP-MatB, via strain-promoted azide-alkyne cycloaddition (SPAAC), the DNA-/NTA-functionalized HA macromer was utilized as base material together with maleimide-functionalized PEG (PEG-mal2) as the crosslinker to form bifunctional microgels utilizing water-in-oil (W/O) microemulsions. As-formed microgels were incubated with nickel sulfate to activate the NTA groups and provide binding sites for deGFP-MatB, which contained six histidine residues (His-tag) for that purpose. The optimized CFPS mixture was loaded into the microgels to initiate the formation of deGFP-MatB, which was detected by a clear increase in fluorescence exclusively inside the microgel volume. Functionality of both, the bound and the decoupled enzyme was proven by reaction with malonate to yield malonyl CoA, as confirmed by a colorimetric assay. © 2020 The Royal Society of Chemistry.