Concentration-Independent Multivalent Targeting of Cancer Cells by Genetically Encoded Core-Crosslinked Elastin/Resilin-like Polypeptide Micelles.

Valency is a fundamental principle to control macromolecular interactions and is used to target specific cell types by multivalent ligand-receptor interactions using self-assembled nanoparticle carriers. At the concentrations encountered in solid tumors upon systemic administration, these nanoparticles are, however, likely to show critical micelle concentration (CMC)-dependent disassembly and thus loss of function. To overcome this limitation, core-crosslinkable micelles of genetically encoded resilin-/elastin-like diblock polypeptides were recombinantly synthesized.

Quantitative Study of the Interaction of Multivalent Ligand-Modified Nanoparticles with Breast Cancer Cells with Tunable Receptor Density.

Multivalent nanoparticles that target a cell surface receptor that is overexpressed by cancer cells are a promising delivery system for cancer therapy. However, the impact of the receptor density and nanoparticle ligand valency on the cell uptake has not been studied in a system where both variables can be systematically tuned over a wide range. To address this lacuna, we report cell-uptake studies on a genetically engineered breast cancer cell line with tunable ErbB2 expression by a polypeptide micelle with tunable ligand valency.

A Recombinant Secondary Antibody Mimic as a Target-specific Signal Amplifier and an Antibody Immobilizer in Immunoassays.

We construct a novel recombinant secondary antibody mimic, GST-ABD, which can bind to the Fc regions of target-bound primary antibodies and acquire multiple HRPs simultaneously. We produce it in tenth of mg quantities with a bacterial overexpression system and simple purification procedures, significantly reducing the manufacturing cost and time without the use of animals. GST-ABD is effectively conjugated with 3 HRPs per molecule on an average and selectively bind to the Fc region of primary antibodies derived from three different species (mouse, rabbit, and rat).

An enhanced ascorbate peroxidase 2/antibody-binding domain fusion protein (APEX2-ABD) as a recombinant target-specific signal amplifier.

A recombinant target-specific signal amplifier was constructed by genetically fusing the enhanced ascorbate peroxidase 2 (APEX2) and an antibody-binding domain (ABD). The fusion protein APEX2-ABD possessed the peroxidase activity and the antibody-binding capability simultaneously and replaced the conventional HRP-conjugated secondary antibodies in a TSA assay for amplifying fluorescence signals.

Developing genetically engineered encapsulin protein cage nanoparticles as a targeted delivery nanoplatform.

Protein cage nanoparticles are excellent candidates for use as multifunctional delivery nanoplatforms because they are built from biomaterials and have a well-defined structure. A novel protein cage nanoparticle, encapsulin, isolated from thermophilic bacteria Thermotoga maritima, is prepared and developed as a versatile template for targeted delivery nanoplatforms through both chemical and genetic engineering. It is pivotal for multifunctional delivery nanoplatforms to have functional plasticity and versatility to acquire targeting ligands, diagnostic probes, and drugs simultaneously.

Development of P22 viral capsid nanocomposites as anti-cancer drug, bortezomib (BTZ), delivery nanoplatforms.

Genetic and chemical engineering approaches are used to employ P22 viral capsids as nanoplatforms for developing an efficient delivery vehicle. Catechol ligands are chemically attached to the interior surface of P22 viral capsid for subsequent encapsulation of an anticancer drug, bortezomib (BTZ), through boronic acid-diol complexation. For targeted delivery, hepatocellular carcinoma (HCC)-targeting peptide (SP94, SFSIIHTPILPL) is synthesized and chemically conjugated to the exterior surface of the P22 viral capsid nanocomposites.

Genetically engineering encapsulin protein cage nanoparticle as a SCC-7 cell targeting optical nanoprobe.

Background: Protein cage nanoparticles are promising nanoplatform candidates for efficient delivery systems of diagnostics and/or therapeutics because of their uniform size and structure as well as high biocompatibility and biodegradability. Encapsulin protein cage nanoparticle is used to develop a cell-specific targeting optical nanoprobe.

Results: FcBPs are genetically inserted and successfully displayed on the surface of encapsulin to form FcBP-encapsulin.

Implementation of P22 viral capsids as intravascular magnetic resonance T1 contrast conjugates via site-selective attachment of Gd(III)-chelating agents.

P22 viral capsids and ferritin protein cages are utilized as templating macromolecules to conjugate Gd(III)-chelating agent complexes, and we systematically investigates the effects of the macromolecules' size and the conjugation positions of Gd(III)-chelating agents on the magnetic resonance (MR) relaxivities and the resulting image contrasts. The relaxivity values of the Gd(III)-chelating agent-conjugated P22 viral capsids (outer diameter: 64 nm) are dramatically increased as compared to both free Gd(III)-chelating agents and Gd(III)-chelating agent-conjugated ferritins (outer diameter: 12 nm), suggesting that the large sized P22 viral capsids exhibit a much slower tumbling rate, which results in a faster T1 relaxation rate. Gd(III)-chelating agents are attached to either the interior or exterior surface of P22 viral capsids and the conjugation positions of Gd(III)-chelating agents, however, do not have a significant effect on the relaxivity values of the macromolecular conjugates.