An in situ gelling liquid crystalline system based on monoglycerides and polyethylenimine for local delivery of siRNAs.
The development of delivery systems able to complex and release siRNA into the cytosol is essential for therapeutic use of siRNA. Among the delivery systems, local delivery has advantages over systemic administration. In this study, we developed and characterized non-viral carriers to deliver siRNA locally, based on polyethylenimine (PEI) as gene carrier, and a self-assembling drug delivery system that forms a gel in situ. Liquid crystalline formulations composed of monoglycerides (MO), PEI, propylene glycol (PG) and 0.1M Tris buffer pH 6.5 were developed and characterized by polarized light microscopy, Small Angle X-ray Scattering (SAXS), for their ability to form inverted type liquid crystalline phases (LC2) in contact with excess water, water absorption capacity, ability to complex with siRNA and siRNA release. In addition, gel formation in vivo was determined by subcutaneous injection of the formulations in mice. In water excess, precursor fluid formulations rapidly transformed into a viscous liquid crystalline phase. The presence of PEI influences the liquid crystalline structure of the LC2 formed and was crucial for complexing siRNA. The siRNA was released from the crystalline phase complexed with PEI. The release rate was dependent on the rate of water uptake. The formulation containing MO/PEI/PG/Tris buffer at 7.85:0.65:76.5:15 (w/w/w/w) complexed with 10 μM of siRNA, characterized as a mixture of cubic phase (diamond-type) and inverted hexagonal phase (after contact with excess water), showed sustained release for 7 days in vitro. In mice, in situ gel formation occurred after subcutaneous injection of the formulations, and the gels were degraded in 30 days. Initially a mild inflammatory process occurred in the tissue surrounding the gel; but after 14 days the tissue appeared normal. Taken together, this work demonstrates the rational development of an in situ gelling formulation for local release of siRNA.
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
Lívia Neves
LN
Borgheti-Cardoso
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
Lívia Vieira
LV
Depieri
Laboratory of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Sander A A
SA
Kooijmans
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
Henrique
H
Diniz
Universidad de La Frontera, Avenida Francisco Salazar 01145, Temuco, Chile.
Ricardo Alexandre Junqueira
RA
Calzzani
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil.
Fabiana Testa Moura de Carvalho
FT
Vicentini
Laboratory of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Roy
R
van der Meel
Instituto de Física, Universidade de São Paulo, São Paulo, SP, Brazil.
Márcia Carvalho de Abreu
MC
Fantini
Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
Mamie Mizusaki
MM
Iyomasa
Laboratory of Clinical Chemistry and Haematology, University Medical Center Utrecht, Utrecht, The Netherlands.
Raymond M
RM
Schiffelers
Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café, s/n, 14040-903 Ribeirão Preto, SP, Brazil. Electronic address: vbentley@usp.br.
Maria Vitória Lopes Badra
MV
Bentley
D000818:Animals; D002481:Cellulitis / Q000139:chemically induced / Q000276:immunology / Q000473:pathology / Q000517:prevention & control*; D005260:Female; D005782:Gels; D018014:Gene Transfer Techniques / Q000009:adverse effects*; D005989:Glycerides / Q000009:adverse effects / Q000737:chemistry; D007279:Injections, Subcutaneous; D008807:Mice, Inbred BALB C; D050178:Monoglycerides / Q000009:adverse effects / Q000737:chemistry; D011094:Polyethyleneimine / Q000009:adverse effects / Q000737:chemistry*; D019946:Propylene Glycol / Q000009:adverse effects / Q000737:chemistry; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000009:adverse effects / Q000737:chemistry; D000067492:RNAi Therapeutics / Q000009:adverse effects*; D012867:Skin / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D012995:Solubility; D040521:Subcutaneous Tissue / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D055682:Viscoelastic Substances / Q000009:adverse effects / Q000737:chemistry*; D014783:Viscosity; D014867:Water / Q000032:analysis
D005782:Gels; D005989:Glycerides; D050178:Monoglycerides; D034741:RNA, Small Interfering; D055682:Viscoelastic Substances; D014867:Water; D019946:Propylene Glycol; D011094:Polyethyleneimine; C005953:monoolein
Liquid crystal; Local release; Non-viral gene delivery; Self-assembly; siRNA