Provided herein are polypeptides that bind to a blood-brain barrier (BBB) receptor, methods of generating such polypeptides, and methods of using the polypeptides to target a composition to a BBB receptor-expressing cell, e.g., for transport across the BBB. Also provided herein are transferrin receptor (TfR) constructs that comprise a monomeric TfR apical domain or one or more portions of the TfR apical domain which have been circularly permuted relative to the full-length TfR sequence.

In one aspect, bispecific proteins having the ability to specifically bind to two antigens, and having an Fc polypeptide that comprises a modified CH3 domain and specifically binds to a transferrin receptor, are provided.

An engineered AAV capsid is provided, in which at least one protein on the capsid is modified to include a n-mer motif, which promotes transduction of the capsid into the central nervous system (CNS) through interaction with the Transferrin receptor. Further embodiments provide a vector system comprising one or more vectors encoding AAV capsids and a method of delivering cargo to the CNS. The method comprises administering, in vivo or in vitro, a AAV capsid according to embodiments described herein and the AVV capsid comprises one or more cargo molecules.

The present invention relates to engineered extracellular vesicles (EVs) as a therapeutic modality for the treatment of various severe diseases. More specifically, the invention relates to a novel approach to manufacturing engineered EVs which extends their half-life and alters their biodistribution, resulting in a novel therapeutic modality able to carry various types of drugs suitable for application in not only genetic diseases but more broadly across essentially all therapeutic areas.

Methods for the in vitro production of enucleated red blood cells and the enucleated red blood cells thus prepared are provided. Such enucleated red blood cells may express a sortaggable surface protein, which allows for surface modification in the presence of a sortase. Also described herein are surface modified enucleated red blood cells, e.g., conjugated with an agent of interest such as a peptide, a detectable label, or a chemotherapeutic agent, and uses thereof in delivering the agent to a subject.

The present disclosure relates to polypeptides, such as fibronectin type III (FN3) domains that can bind CD71, their conjugates, isolated nucleotides encoding the molecules, vectors, host-cells, as well as methods of making and using the same.

A composition of matter comprising an isolated soluble polypeptide comprising an amino acid sequence of a Transferrin receptor protein 1 (TfR1) apical domain is disclosed, the soluble polypeptide being capable of binding an Arenavirus. A fusion protein comprising an amino acid sequence of a TfR1 apical domain and an amino acid sequence of IgG Fc, the fusion protein capable of binding an Arenavirus, is also disclosed.

Provided herein are polypeptides that bind to a blood-brain barrier (BBB) receptor, methods of generating such polypeptides, and methods of using the polypeptides to target a composition to a BBB receptor-expressing cell, e.g., for transport across the BBB. Also provided herein are transferrin receptor (TfR) constructs that comprise a monomeric TfR apical domain or one or more portions of the TfR apical domain which have been circularly permuted relative to the full-length TfR sequence.

Provided herein are polypeptides that bind to a transferrin receptor, methods of generating such polypeptides, and methods of using the polypeptides to target a composition to a transferrin receptor-expressing cell.

A novel human bladder cancer marker AG-CD71 and a monoclonal antibody ABC71 for preventing AG-CD71 are provided. The human bladder cancer marker AG-CD71 is an abnormal glycosylated transferrin receptor TFRC; the abnormal glycosylated transferrin receptor TFRC refers to the TFRC carrying a saccharide structure Fucal-4(GlcNAcbl-3)[6OSO3]GlcNAc as an epitope. Also provided is an antibody for the human bladder cancer marker AG-CD71; the antibody is the monoclonal antibody ABC71 specific for the human bladder cancer AG-CD71; the monoclonal antibody is secreted from the hybridoma cell to strain the preservation number of which is CGMCC No. 14312.