Antibody-Conjugated, DNA-Based Nanocarriers Intercalated with Doxorubicin Eliminate Myofibroblasts in Explants of Human Lens Tissue

Abstract

Posterior capsule opacification (PCO) occurs in some adults and most children following cataract surgery. The fibrotic form of PCO arises, in part, from migratory, contractile myofibroblasts that deform the lens capsule and impair vision. In short-term cultures of human anterior lens tissue, myofibroblasts emerge from Myo/Nog cells that are identified with the G8 monoclonal antibody and by their expression of the MyoD transcription factor and bone morphogenetic protein inhibitor noggin. In this study, we tested the hypothesis that targeted depletion of Myo/Nog cells with the G8 monoclonal antibody (mAb) conjugated to three-dimensional DNA nanocarriers intercalated with doxorubicin (G8:3DNA:Dox) would prevent the accumulation of myofibroblasts in long-term, serum- and growth factor-free cultures of human lens tissue obtained by capsulorhexis. The mAb:nanocarrier complex was internalized into acidic compartments of the cell. G8:3DNA:Dox killed nearly all Myo/Nog cells without affecting the lens epithelial cells. In 30-day cultures, all G8-positive cells expressed noggin, and subpopulations had synthesized MyoD, sarcomeric myosin, and alpha smooth muscle actin (-SMA). Myo/Nog cells responded to scratching of the lens epithelium by accumulating around the edges of the wound. Treatment with two doses of G8:3DNA:Dox completely eliminated G8+/-SMA+ cells throughout the explant. These experiments demonstrate that Myo/Nog cells are the source of myofibroblasts in long-term cultures of anterior human lens tissue and mAb:3DNA nanocarriers specifically and effectively deliver cytotoxic cargo to a subpopulation of cells without off-target effects. G8:3DNA:Dox has the potential to reduce PCO following cataract surgery.

Decreased microglial Wnt/β-catenin signalling drives microglial pro-inflammatory activation in the developing brain

“…The 3DNA nanocarrier is a powerful translational tool as is it can take agents across the BBB following i.p. injection, is specifically internalized by MG/Mφ in the brain and it has no toxicity in vitro or in vivo in our study, or in human retinal tissue in vitro (Gerhart et al, 2017) and in pre-clinical in vivo targeted delivery of a ovarian cancer therapy (Huang et al, 2016).…”

Loss of the Wnt/β-catenin pathway in microglia of the developing brain drives pro-inflammatory activation leading to white matter injury

“…The 3DNA nanocarrier is a powerful translational tool as is it can take agents across the BBB following i.p. injection, is specifically internalized by MG/Mφ in the brain and it has no toxicity in vitro or in vivo in our study, or in human retinal tissue in vitro (Gerhart et al 2017) and in pre-clinical in vivo targeted delivery of a ovarian cancer therapy (Huang et al 2016). Wnt activation in OPCs has previously been suggested to block their maturation by a member of our current research team (Fancy et al 2011).…”

Depletion of Myo/Nog Cells in the Lens Mitigates Posterior Capsule Opacification in Rabbits

“…24,28,30 Myo/Nog cells also react to wounding in the embryo and adult. [30][31][32][33][34][35][36][37] Within 24 hours of epidermal abrasion, Myo/Nog cells increase in number and populate the wound. 38 In the retina, the Myo/Nog population expands in response to hypoxia and damaging levels of light.…”

“…In the human lens, Myo/Nog cells surround wounds, synthesize a-SMA and skeletal muscle proteins, and overlie wrinkles in the capsule. 32,33 Depletion of Myo/Nog cells with the targeting G8 monoclonal antibody (mAb) bound to complement or conjugated to two-layered 3DNA nanocarriers intercalated with the cytotoxin doxorubicin (G8:3DNA:Dox) prevents the emergence of myofibroblasts in response to wounding in explant cultures of chick embryo and human anterior lens tissue. 32,33,37 The behavior of Myo/Nog cells in the lens in vivo has been studied in rabbits.…”