Chitosan-shelled oxygen-loaded nanodroplets abrogate hypoxia dysregulation of human keratinocyte gelatinases and inhibitors: New insights for chronic wound healing.
BACKGROUND
In chronic wounds, efficient epithelial tissue repair is hampered by hypoxia, and balances between the molecules involved in matrix turn-over such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are seriously impaired. Intriguingly, new oxygenating nanocarriers such as 2H,3H-decafluoropentane-based oxygen-loaded nanodroplets (OLNs) might effectively target chronic wounds.


OBJECTIVE
To investigate hypoxia and chitosan-shelled OLN effects on MMP/TIMP production by human keratinocytes.


METHODS
HaCaT cells were treated for 24h with 10% v/v OLNs both in normoxia or hypoxia. Cytotoxicity and cell viability were measured through biochemical assays; cellular uptake by confocal microscopy; and MMP and TIMP production by enzyme-linked immunosorbent assay or gelatin zymography.


RESULTS
Normoxic HaCaT cells constitutively released MMP-2, MMP-9, TIMP-1 and TIMP-2. Hypoxia strongly impaired MMP/TIMP balances by reducing MMP-2, MMP-9, and TIMP-2, without affecting TIMP-1 release. After cellular uptake by keratinocytes, nontoxic OLNs abrogated all hypoxia effects on MMP/TIMP secretion, restoring physiological balances. OLN abilities were specifically dependent on time-sustained oxygen diffusion from OLN core.


CONCLUSIONS
Chitosan-shelled OLNs effectively counteract hypoxia-dependent dysregulation of MMP/TIMP balances in human keratinocytes. Therefore, topical administration of exogenous oxygen, properly encapsulated in nanodroplet formulations, might be a promising adjuvant approach to promote healing processes in hypoxic wounds.
Dipartimento di Neuroscienze, Università di Torino, Torino, Italy.
Amina
A
Khadjavi
Istituto Nazionale di Ricerca Metrologica (INRIM), Torino, Italy.
Chiara
C
Magnetto
Dipartimento di Scienze della Salute, Università di Milano Bicocca, Monza, Italy.
Alice
A
Panariti
Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Torino, Italy.
Monica
M
Argenziano
Dipartimento di Oncologia, Università di Torino, Torino, Italy.
Giulia Rossana
GR
Gulino
Dipartimento di Scienze della Salute, Università di Milano Bicocca, Monza, Italy.
Ilaria
I
Rivolta
Dipartimento di Scienza e Tecnologia del Farmaco, Università di Torino, Torino, Italy.
Roberta
R
Cavalli
Dipartimento di Oncologia, Università di Torino, Torino, Italy.
Giuliana
G
Giribaldi
Dipartimento di Neuroscienze, Università di Torino, Torino, Italy.
Caterina
C
Guiot
Dipartimento di Neuroscienze, Università di Torino, Torino, Italy; Dipartimento di Scienze della Sanità Pubblica e Pediatriche, Università di Torino, Torino, Italy. Electronic address: mauro.prato@unito.it.
Mauro
M
Prato
D015687:Cell Hypoxia / Q000187:drug effects / Q000502:physiology; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D048271:Chitosan / Q000008:administration & dosage* / Q000737:chemistry; D004337:Drug Carriers / Q000008:administration & dosage / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018093:Gelatinases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000201:enzymology; D008297:Male; D008875:Middle Aged; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry; D010100:Oxygen / Q000008:administration & dosage* / Q000737:chemistry; D014945:Wound Healing / Q000187:drug effects* / Q000502:physiology
D004337:Drug Carriers; D004791:Enzyme Inhibitors; D048271:Chitosan; D018093:Gelatinases; D010100:Oxygen
Chitosan; Hypoxia; Keratinocyte; Matrix metalloproteinase (MMP); Nanodroplet; Tissue inhibitor of metalloproteinase (TIMP)