In vivo biocompatibility evaluation of in situ-forming polyethylene glycol-collagen hydrogels in corneal defects

AbstractThe available treatment options include corneal transplantation for significant corneal defects and opacity. However, shortage of donor corneas and safety issues in performing corneal transplantation are the main limitations. Accordingly, we adopted the injectable in situ-forming hydrogels of collagen type I crosslinked via multifunctional polyethylene glycol (PEG)-N-hydroxysuccinimide (NHS) for treatment and evaluated in vivo biocompatibility. The New Zealand White rabbits (N = 20) were randomly grouped into the keratectomy-only and keratectomy with PEG-collagen hydrogel-treated groups. Samples were processed for immunohistochemical evaluation. In both clinical and histologic observations, epithelial cells were able to migrate and form multilayers over the PEG-collagen hydrogels at the site of the corneal stromal defect. There was no evidence of inflammatory or immunological reactions or increased IOP for PEG-collagen hydrogel-treated corneas during the four weeks of observation. Immunohistochemistry revealed the presence of α-smooth muscle actin (α-SMA) in the superior corneal stroma of the keratectomy-only group (indicative of fibrotic healing), whereas low stromal α-SMA expression was detected in the keratectomy with PEG-collagen hydrogel-treated group. Taken together, we suggest that PEG-collagen may be used as a safe and effective alternative in treating corneal defect in clinical setting.

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In situ-forming collagen hydrogel crosslinked via multi-functional PEG as a matrix therapy for corneal defects

Scientific Reports ◽

10.1038/s41598-020-72978-5 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Gabriella Maria Fernandes-Cunha ◽

Karen Mei Chen ◽

Fang Chen ◽

Peter Le ◽

Ju Hee Han ◽

...

Keyword(s):

Patient Comfort ◽

In Vivo Studies ◽

Corneal Transplant ◽

Type I ◽

Corneal Tissue ◽

In Situ Forming ◽

Collagen Hydrogels ◽

Donor Corneas

Abstract Visually significant corneal injuries and subsequent scarring collectively represent a major global human health challenge, affecting millions of people worldwide. Unfortunately, less than 2% of patients who could benefit from a sight-restoring corneal transplant have access to cadaveric donor corneal tissue. Thus, there is a critical need for new ways to repair corneal defects that drive proper epithelialization and stromal remodeling of the wounded area without the need for cadeveric donor corneas. Emerging therapies to replace the need for donor corneas include pre-formed biosynthetic buttons and in situ-forming matrices that strive to achieve the transparency, biocompatibility, patient comfort, and biointegration that is possible with native tissue. Herein, we report on the development of an in situ-forming hydrogel of collagen type I crosslinked via multi-functional polyethylene glycol (PEG)-N-hydroxysuccinimide (NHS) and characterize its biophysical properties and regenerative capacity both in vitro and in vivo. The hydrogels form under ambient conditions within minutes upon mixing without the need for an external catalyst or trigger such as light or heat, and their transparency, degradability, and stiffness are modulated as a function of number of PEG arms and concentration of PEG. In addition, in situ-forming PEG-collagen hydrogels support the migration and proliferation of corneal epithelial and stromal cells on their surface. In vivo studies in which the hydrogels were formed in situ over stromal keratectomy wounds without sutures showed that they supported multi-layered surface epithelialization. Overall, the in situ forming PEG-collagen hydrogels exhibited physical and biological properties desirable for a corneal stromal defect wound repair matrix that could be applied without the need for sutures or an external trigger such as a catalyst or light energy.

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mTOR inhibitors potentially reduce TGF-β2-induced fibrogenic changes in trabecular meshwork cells

Scientific Reports ◽

10.1038/s41598-021-93580-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Nozomi Igarashi ◽

Megumi Honjo ◽

Makoto Aihara

Keyword(s):

Trabecular Meshwork ◽

Transforming Growth Factor ◽

Smooth Muscle Actin ◽

Mtor Inhibitors ◽

In Vivo Model ◽

Type I ◽

Fibrotic Response ◽

Alpha Smooth Muscle Actin

AbstractWe examined the effects of mTOR inhibitors on the fibrotic response induced by transforming growth factor-beta2 (TGF-β2) in cultured human trabecular meshwork (hTM) cells. TGF-β2-induced expression of fibronectin, collagen type I, alpha 1 chain (COL1A1), and alpha-smooth muscle actin (αSMA) in hTM cells was examined in the presence or absence of mTOR inhibitors using quantitative real-time polymerase chain reaction, Western blotting, and immunohistochemistry. The migration rates of hTM cells were examined in the presence of TGF-β2 with or without mTOR inhibitors. An in vitro study showed that the expression of fibronectin, COL1A1, and αSMA was upregulated by TGF-β2 treatment of hTM cells; such upregulation was significantly suppressed by mTOR inhibitors. The inhibitors significantly reduced the migration rate of TGF-β2-stimulated hTM cells. mTOR inhibitors may usefully reduce the fibrotic response of hTM cells and we may have to explore if it is also effective in in vivo model.

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The osteogenic differentiation of rat muscle-derived stem cells in vivo within in situ-forming chitosan scaffolds

Biomaterials ◽

10.1016/j.biomaterials.2008.08.005 ◽

2008 ◽

Vol 29 (33) ◽

pp. 4420-4428 ◽

Cited By ~ 51

Author(s):

Kyung Sook Kim ◽

Jung Hwa Lee ◽

Hyun Hee Ahn ◽

Ju Young Lee ◽

Gilson Khang ◽

...

Keyword(s):

Stem Cells ◽

Osteogenic Differentiation ◽

Rat Muscle ◽

In Situ Forming ◽

Chitosan Scaffolds

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In situ forming chitosan hydrogels: Preliminary evaluation of the in vivo inflammatory response

Materials Science and Engineering C ◽

10.1016/j.msec.2017.02.050 ◽

2017 ◽

Vol 75 ◽

pp. 279-285 ◽

Cited By ~ 9

Author(s):

Maria José Moura ◽

João Brochado ◽

Maria Helena Gil ◽

Maria Margarida Figueiredo

Keyword(s):

Inflammatory Response ◽

Preliminary Evaluation ◽

In Situ Forming ◽

Chitosan Hydrogels

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In Vitro and In Vivo Drug Release from a Novel In Situ Forming Drug Delivery System

Pharmaceutical Research ◽

10.1007/s11095-007-9478-y ◽

2007 ◽

Vol 25 (6) ◽

pp. 1347-1354 ◽

Cited By ~ 38

Author(s):

Heiko Kranz ◽

Erol Yilmaz ◽

Gayle A. Brazeau ◽

Roland Bodmeier

Keyword(s):

Drug Delivery ◽

Drug Release ◽

Drug Delivery System ◽

Delivery System ◽

In Situ Forming

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Curcumin-incorporated crosslinked sodium alginate-g-poly (N-isopropyl acrylamide) thermo-responsive hydrogel as an in-situ forming injectable dressing for wound healing: in vitro characterization and in vivo evaluation

Carbohydrate Polymers ◽

10.1016/j.carbpol.2021.118434 ◽

2021 ◽

pp. 118434

Author(s):

Mohammad Zakerikhoob ◽

Sahar Abbasi ◽

Gholamhossein Yousefi ◽

Maral Mokhtari ◽

Mohammad Sadegh Noorbakhsh

Keyword(s):

Wound Healing ◽

Sodium Alginate ◽

In Vivo Evaluation ◽

In Situ Forming ◽

In Vitro Characterization ◽

Isopropyl Acrylamide

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In-vitro, ex-vivo, and in-vivo release evaluation of in situ forming buprenorphine implants using mixture of PLGA copolymers and additives

International Journal of Polymeric Materials ◽

10.1080/00914037.2018.1525541 ◽

2018 ◽

Vol 68 (16) ◽

pp. 965-977 ◽

Cited By ~ 1

Author(s):

Hossein Kamali ◽

Elham Khodaverdi ◽

Farzin Hadizadeh ◽

Seyed Ahmad Mohajeri ◽

Younes Kamali ◽

...

Keyword(s):

Ex Vivo ◽

In Situ Forming ◽

In Vivo Release

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Alpha-single chains of collagen type VI inhibit the fibrogenic effects of triple helical collagen VI in hepatic stellate cells

PLoS ONE ◽

10.1371/journal.pone.0254557 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0254557

Author(s):

Christian Freise ◽

Hyunho Lee ◽

Christopher Chronowski ◽

Doug Chan ◽

Jessica Cziomer ◽

...

Keyword(s):

Hepatic Stellate Cells ◽

Collagen Type ◽

Stellate Cell ◽

Smooth Muscle Actin ◽

Stellate Cells ◽

Collagen Type I ◽

Serum Starvation ◽

Type I ◽

Linear Peptide

The interaction of extracellular matrix (ECM) components with hepatic stellate cells (HSCs) is thought to perpetuate fibrosis by stimulating signaling pathways that drive HSC activation, survival and proliferation. Consequently, disrupting the interaction between ECM and HSCs is considered a therapeutical avenue although respective targets and underlying mechanisms remain to be established. Here we have interrogated the interaction between type VI collagen (CVI) and HSCs based on the observation that CVI is 10-fold upregulated during fibrosis, closely associates with HSCs in vivo and promotes cell proliferation and cell survival in cancer cell lines. We exposed primary rat HSCs and a rat hepatic stellate cell line (CFSC) to soluble CVI and determined the rate of proliferation, apoptosis and fibrogenesis in the absence of any additional growth factors. We find that CVI in nanomolar concentrations prevents serum starvation-induced apoptosis. This potent anti-apoptotic effect is accompanied by induction of proliferation and acquisition of a pronounced pro-fibrogenic phenotype characterized by increased α-smooth muscle actin, TGF-β, collagen type I and TIMP-1 expression and diminished proteolytic MMP-13 expression. The CVI-HSC interaction can be disrupted with the monomeric α2(VI) and α3(VI) chains and abrogates the activating CVI effects. Further, functional relevant α3(VI)—derived 30 amino acid peptides lead to near-complete inhibition of the CVI effect. In conclusion, CVI serves as a potent mitogen and activating factor for HSCs. The antagonistic effects of the CVI monomeric chains and peptides point to linear peptide sequences that prevent activation of CVI receptors which may allow a targeted antifibrotic therapy.

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Isoform-specific expression and function of neuregulin

Development ◽

10.1242/dev.124.18.3575 ◽

1997 ◽

Vol 124 (18) ◽

pp. 3575-3586 ◽

Cited By ~ 6

Author(s):

D. Meyer ◽

T. Yamaai ◽

A. Garratt ◽

E. Riethmacher-Sonnenberg ◽

D. Kane ◽

...

Keyword(s):

Biological Effects ◽

Type I ◽

Mouse Development ◽

Specific Expression ◽

Independent Functions ◽

Cell Growth And Differentiation ◽

Cranial Ganglia ◽

And Function

Neuregulin (also known as NDF, heregulin, ARIA, GGF or SMDF), induces cell growth and differentiation. Biological effects of neuregulin are mediated by members of the erbB family of tyrosine kinase receptors. Three major neuregulin isoforms are produced from the gene, which differ substantially in sequence and in overall structure. Here we use in situ hybridization with isoform-specific probes to illustrate the spatially distinct patterns of expression of the isoforms during mouse development. Ablation of the neuregulin gene in the mouse has demonstrated multiple and independent functions of this factor in development of both the nervous system and the heart. We show here that targeted mutations that affect different isoforms result in distinct phenotypes, demonstrating that isoforms can take over specific functions in vivo. Type I neuregulin is required for generation of neural crest-derived neurons in cranial ganglia and for trabeculation of the heart ventricle, whereas type III neuregulin plays an important role in the early development of Schwann cells. The complexity of neuregulin functions in development is therefore due to independent roles played by distinct isoforms.

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