Table 1 Summary of a number of studies concerning the use of single-chain antibodies in drug delivery systems.

Temozolomide (TMZ)-loaded IL (scL-TMZ)

anti-transferrin receptor scFv

U87, U251, U87R (a TMZ-resistant subclone of U87) Mice bearing glioblastoma multiforme tumors

Enhanced killing activity against U87 and U251 cells (compared with noncapsulated TMZ), sensitization of U87R to TMZ.

(72)

Fusion peptide composed of scFv format of PiPP mAb and pseudomonas exotoxin (PE38)

human chorionic gonadotropin (hCG)-specific scFv

hCG-expressing cells (U937, MOLT4 and A549 cells)

Prolonged animal survival time killing of hCG-expressing cancer cells without affecting PBMCs

(73)

Fusion peptide composed of viral interleukin-10 (vIL-10), MMP cleavable linker and anti-ROS-CII scFv

An scFv-targeting ROS-modified collagen type II (anti-ROS-CII scFv)

mouse MC-9 mast cells + arthritic C57BL/6 mice

Increased cell proliferation + Specific localization in arthritic knee + reduced inflammation

(74)

Mixing of doxorubicin-loaded mPEG-NPs and BsAbs

humanized 15-2b anti-mPEG Fab fragment

SW480 (EGFR+ cells) and SK-BR-3 (HER2⁺ cells

Preferential binding to EGFR⁺/HER2⁺ cancer cells

(75)

(noncovalent binding)

+ human anti-EGFR scFv/anti-HER2-scFv

BALB/c nude mice bearing xenograft of SW480/SW620 cells

Significantly increased suppression of tumor growth when compared with nontargeted nanoparticles

Azido-functionalized protein nanocapsules loaded with GFP

Anti-HER2-scFv

SKBR3 (HER-2-overexpressing cell line) and MDA-MB-231 (triple-negative cell line)

Specific delivery of GFP to SKBR3 cells + no florescence in MDA-MB-231 cells

(76)

scFv-CD40L fusion peptide (EpCAM:CD40L)

Anti-EpCAM scFv

EpCAM-transfectant cell line HEK293. EpCAM

Induction of paracrine CD40 signaling in tumor-resident immature dendritic cells (iDC), maturation of DCs + activation of T cells.

(77)

scFv-CD40L fusion peptide (−CD20:CD40L)

Anti-CD20 scFv

CD20⁺ leukemic B cells (BJAB and Raji)

Induction of CD40 signaling, induction of cell death

Fusion peptide composed of Bluetongue virus VP2 protein and APCH

APCH (an scFv recognizing antigen-presenting cells)

guinea pigs, IFNAR^−/− mice, and cattle

Enhanced humoral and cellular immune response in IFNAR^−/− mice (when compared with VP2 alone + high titer of specific NAs in pigs and cattle

(78)

Fusion peptide composed of an anti-EGFR VHH and iRGD (a tumor-penetrating peptide, CRGDK GPDC)

VHH (variable domain of heavy chain of anti-EGFR antibody)

2D culture, multicellular spheroids (3D) culture, and tumor xenograft of BGC-823 cells (Human gastric adenocarcinoma cell line)

Enhanced antitumor activity when compared with anti-EGFR antibody alone + penetration into deeper zone of multicellular spheroids and tumors + ...

(79)

crosslinked albumin nanoparticles targeting HGFR (c-Met)

Anti-HGFR nanobody (Anti-c-Met nanobody)

TOV-112D (Met-negative cells), TOV + Met (Met-transfected TOV-112D cells), MKN45, A549, A431

Specific binding to Met-expressing cells + internalization and lysosomal degradation of Met-targeted nanoparticles (evaluated in MKN45 and A549 cells)

(80)

Fusion peptide composed of scFv and nuclear localization signal (NLS)

scFv-targeting nuclear export signal (NES, C-terminus of mutated NPMc⁺)

NPMc + -transfected HeLa cells and OCI-AML3 (human acute myeloid leukemia cells)

Accumulation of fusion peptide in the nucleus + effective binding to NPMc⁺ in the cytoplasm + failing to relocate NPMc⁺ in the nucleus

(81)

Rous sarcoma virus-like particles Displaying scFv antibody

scFv format of humanized CC49 antibody (anti-TAG-72 antibody)

LS174T human colon adenocarcinoma Cells (TAG-72-expressing cells) + HEK293 cells (control cells)

Selectively killing of LS174T cells by FITC/DOX-loaded carrier

(82)

scFv-TR1 fusion protein

scFv-specific for mesothelin, a tumor marker

wild-type Jurkat cells

+ J-Meso (Jurkat cells engineered to express human mesothelin)

+ OVCAR3 (ovarian cancer cell line-expressing mesothelin)

Selectively killing of mesothelin-positive cells

(83)