51 research outputs found
Design, Synthesis, Characterization, and Antiproliferative Activity of Organoplatinum Compounds Bearing a 1,2,3-Triazole Ring
The syntheses, characterizations,
and biological activities of
three organoplatinum compounds, each containing a triazole ring, are
discussed. These organometallic compounds demonstrate superior cytotoxicity
against osteosarcoma and human breast cancer cells relative to cisplatin,
a well-known chemotherapeutic agent used for chemotherapy
Potential of Agarose/Silk Fibroin Blended Hydrogel for in Vitro Cartilage Tissue Engineering
An
osteoarthritis pandemic has accelerated exploration of various
biomaterials for cartilage reconstruction with a special emphasis
on silk fibroin from mulberry (<i>Bombyx mori</i>) and non-mulberry
(<i>Antheraea assamensis</i>) silk worms. Retention of positive
attributes of the agarose standard and nullification of its negatives
are central to the current agarose/silk fibroin hydrogel design. In
this study, hydrogels of mulberry and non-mulberry silk fibroin blended
with agarose were fabricated and evaluated in vitro for two weeks
for cartilaginous tissue formation. The fabricated hydrogels were
physicochemically characterized and analyzed for cell viability, proliferation,
and extra cellular matrix deposition. The amalgamation of silk fibroin
with agarose impacted the pore size, as illustrated by field emission
scanning electron microscopy studies, swelling behavior, and in vitro
degradation of the hydrogels. Fourier transform infrared spectroscopy
results indicated the blend formation and confirmed the presence of
both components in the fabricated hydrogels. Rheological studies demonstrated
enhanced elasticity of blended hydrogels with <i>G</i>′
> <i>G</i>″. Biochemical analysis revealed significantly
higher levels of sulfated glycosaminoglycans (sGAGs) and collagen
(<i>p</i> ≤ 0.01) in blended hydrogels. More specifically,
the non-mulberry silk fibroin blend showed sGAG and collagen content
(∼1.5-fold) higher than that of the mulberry blend (<i>p</i> ≤ 0.05). Histological and immunohistochemical analyses
further validated the enhanced deposition of sGAG and collagen, indicating
maintenance of chondrogenic phenotype within constructs after two
weeks of culture. Real-time PCR analysis further confirmed up-regulation
of cartilage-specific aggrecan, sox-9 (∼1.5-fold) and collagen
type II (∼2-fold) marker genes (<i>p</i> ≤
0.01) in blended hydrogels. The hydrogels demonstrated immunocompatibility,
which was evidenced by minimal in vitro secretion of tumor necrosis
factor-α (TNF-α) by murine macrophages. Taken together,
the results suggest promising attributes of blended hydrogels and
particularly the non-mulberry silk fibroin/agarose blends as alternative
biomaterial for cartilage tissue engineering
Self-Assembly of a [1 + 1] Ionic Hexagonal Macrocycle and Its Antiproliferative Activity
A unique irregular hexagon was self-assembled using an organic donor clip (bearing terminal pyridyl units) and a complementary organometallic acceptor clip. The resulting metallamacrocycle was characterized by multinuclear NMR, mass spectrometry, and elemental analyses. Molecular modeling confirmed hexagonal shaped cavity for this metallamacrocycle which is a unique example of a discrete hexagonal framework self-assembled from only two building blocks. Cytotoxicity of the Pt-based acceptor tecton and the self-assembled PtII-based macrocycle was evaluated using three cancer cell lines and results were compared with cisplatin. Results confirmed a positive effect of the metallamacrocycle formation on cell growth inhibition
Omentum Extracellular Matrix-Silk Fibroin Hydroscaffold Promotes Wound Healing through Vascularization and Tissue Remodeling in the Diabetic Rat Model
Nonhealing diabetic wounds are often associated with
significant
mortality and cause economic and clinical burdens to the healthcare
system. Herein, a biomimetic hydroscaffold is developed using omentum
tissue-derived decellularized-extracellular matrix (dECM) and silk
fibroin (SF) proteins that associate the behavior of a collagenous
fibrous scaffold and a hydrogel to reproduce all aspects of the provisional
skin tissue matrix. The chemical cross-linker-free in situ gelation
property of the two types of SF proteins from Bombyx
mori and Antheraea assamensis ensures the adherence of dECM with surrounding tissue on the wound
bed, circumventing further suturing. The physicochemical and mechanical
properties of the composite hydroscaffold (SF–dECM) were thoroughly
evaluated. The hydroscaffolds were found to support the growth and
proliferation of human dermal fibroblasts and influence the angiogenic
potential of endothelial cells under in vitro conditions. Furthermore,
the healing efficacy of the composites was evaluated by generating
full-thickness wounds on a streptozotocin-induced diabetic rat model.
The presence of dECM components in the composite facilitated the rate
of wound closure, granulation tissue formation, and re-epithelialization
by providing intrinsic cues to advance the inflammatory stage and
stimulating angiogenesis. Collectively, as an off-the-shelf wound
dressing requiring only a single topical administration, the SF–dECM
hydroscaffold is a promising, cost-effective dressing for the management
of chronic diabetic wounds
Omentum Extracellular Matrix-Silk Fibroin Hydroscaffold Promotes Wound Healing through Vascularization and Tissue Remodeling in the Diabetic Rat Model
Nonhealing diabetic wounds are often associated with
significant
mortality and cause economic and clinical burdens to the healthcare
system. Herein, a biomimetic hydroscaffold is developed using omentum
tissue-derived decellularized-extracellular matrix (dECM) and silk
fibroin (SF) proteins that associate the behavior of a collagenous
fibrous scaffold and a hydrogel to reproduce all aspects of the provisional
skin tissue matrix. The chemical cross-linker-free in situ gelation
property of the two types of SF proteins from Bombyx
mori and Antheraea assamensis ensures the adherence of dECM with surrounding tissue on the wound
bed, circumventing further suturing. The physicochemical and mechanical
properties of the composite hydroscaffold (SF–dECM) were thoroughly
evaluated. The hydroscaffolds were found to support the growth and
proliferation of human dermal fibroblasts and influence the angiogenic
potential of endothelial cells under in vitro conditions. Furthermore,
the healing efficacy of the composites was evaluated by generating
full-thickness wounds on a streptozotocin-induced diabetic rat model.
The presence of dECM components in the composite facilitated the rate
of wound closure, granulation tissue formation, and re-epithelialization
by providing intrinsic cues to advance the inflammatory stage and
stimulating angiogenesis. Collectively, as an off-the-shelf wound
dressing requiring only a single topical administration, the SF–dECM
hydroscaffold is a promising, cost-effective dressing for the management
of chronic diabetic wounds
Omentum Extracellular Matrix-Silk Fibroin Hydroscaffold Promotes Wound Healing through Vascularization and Tissue Remodeling in the Diabetic Rat Model
Nonhealing diabetic wounds are often associated with
significant
mortality and cause economic and clinical burdens to the healthcare
system. Herein, a biomimetic hydroscaffold is developed using omentum
tissue-derived decellularized-extracellular matrix (dECM) and silk
fibroin (SF) proteins that associate the behavior of a collagenous
fibrous scaffold and a hydrogel to reproduce all aspects of the provisional
skin tissue matrix. The chemical cross-linker-free in situ gelation
property of the two types of SF proteins from Bombyx
mori and Antheraea assamensis ensures the adherence of dECM with surrounding tissue on the wound
bed, circumventing further suturing. The physicochemical and mechanical
properties of the composite hydroscaffold (SF–dECM) were thoroughly
evaluated. The hydroscaffolds were found to support the growth and
proliferation of human dermal fibroblasts and influence the angiogenic
potential of endothelial cells under in vitro conditions. Furthermore,
the healing efficacy of the composites was evaluated by generating
full-thickness wounds on a streptozotocin-induced diabetic rat model.
The presence of dECM components in the composite facilitated the rate
of wound closure, granulation tissue formation, and re-epithelialization
by providing intrinsic cues to advance the inflammatory stage and
stimulating angiogenesis. Collectively, as an off-the-shelf wound
dressing requiring only a single topical administration, the SF–dECM
hydroscaffold is a promising, cost-effective dressing for the management
of chronic diabetic wounds
In vitro and in vivo evaluation of the marine sponge skeleton as a bone mimicking biomaterial
This investigation was carried out to identify and characterize marine sponges as potential bioscaffolds in bone tissue engineering. The marine sponge (Biemna fortis) samples were collected from the rocky intertidal region of Anjuna, Goa, India, freeze-dried and converted to pure cristobalite at low temperature. After thorough evaluation of sponge samples by DTA-TGA thermography, XRD, FTIR, SEM and cell cytotoxicity by MTT assay, bare sponge scaffolds were fabricated by firing at 1190 degrees C. These scaffolds were loaded with growth factors (IGF-1 and BMP-2), checked for quasi-dynamic in vitro release kinetics and finally implanted into femoral bone defects in rabbits for up to 90 days, by keeping an empty defect as a control. The in vivo bone healing process was evaluated and compared using chronological radiology, histology, SEM and fluorochrome labeling studies. SEM revealed that the sponge skeleton possesses a collagenous fibrous network consisting of highly internetworked porosity in the size range of 10-220 mu m. XRD and FTIR analysis showed a cristobalite phase with acicular crystals of high aspect ratio, and crystallinity was found to increase from 725 to 1190 degrees C. MTT assay demonstrated the non-cytotoxicity of the samples. A combination of burst and sustained release profile was noticed for both the growth factors and about 74.3% and 83% total release at day 28. In the radiological, histological, scanning electron microscopy and fluorochrome labeling analysis, the IGF-1 impregnated converted sponge scaffold promoted excellent osseous tissue formation followed by the BMP-2 loaded and bare one. These observations suggest that the marine sponge alone and in combination with growth factors is a promising biomaterial for bone repair and bone augmentation
Secondary Chemical Cross-Linking to Improve Mechanical Properties in a Multifaceted Biocompatible Strain Sensor
A new conductive and transparent organohydrogel is developed
with
high stretchability, excellent mechanical, self-healing, antifreezing,
and adhesive properties. A simple one-pot polymerization method is
used to create polyacrylamide cross-linked through N,N′-methylenebis(acrylamide) (MBAA) and divinylbenzene
(DVB). The dual chemical cross-linked gel network is complemented
by several physical cross-links via hydrogen bonding and π–π
interaction. Multiple chemical and physical cross-links are used to
construct the gel network that allows toughness (171 kPa), low modulus
(≈45 kPa), excellent stretchability (>1100%), and self-healing
ability. The use of appropriate proportions of the water/glycerol
binary solvent system ensures efficient environment tolerance (−20
to 40 °C). Phytic acid is used as a conductive filler that provides
excellent conductivity and contributes to the physical cross-linking.
Dopamine is incorporated in the gel matrix, which endows excellent
adhesive property of the gel. The organohydrogel-based strain sensors
are developed with state-independent properties, highly linear dependence,
and excellent antifatigue performance (>100 cycles). Moreover,
during
the practical wearable sensing tests, human motions can be detected,
including speaking, smiling, and joint movement. Additionally, the
sensor is biocompatible, indicating the potential applications for
the next generation of epidermal sensors
Secondary Chemical Cross-Linking to Improve Mechanical Properties in a Multifaceted Biocompatible Strain Sensor
A new conductive and transparent organohydrogel is developed
with
high stretchability, excellent mechanical, self-healing, antifreezing,
and adhesive properties. A simple one-pot polymerization method is
used to create polyacrylamide cross-linked through N,N′-methylenebis(acrylamide) (MBAA) and divinylbenzene
(DVB). The dual chemical cross-linked gel network is complemented
by several physical cross-links via hydrogen bonding and π–π
interaction. Multiple chemical and physical cross-links are used to
construct the gel network that allows toughness (171 kPa), low modulus
(≈45 kPa), excellent stretchability (>1100%), and self-healing
ability. The use of appropriate proportions of the water/glycerol
binary solvent system ensures efficient environment tolerance (−20
to 40 °C). Phytic acid is used as a conductive filler that provides
excellent conductivity and contributes to the physical cross-linking.
Dopamine is incorporated in the gel matrix, which endows excellent
adhesive property of the gel. The organohydrogel-based strain sensors
are developed with state-independent properties, highly linear dependence,
and excellent antifatigue performance (>100 cycles). Moreover,
during
the practical wearable sensing tests, human motions can be detected,
including speaking, smiling, and joint movement. Additionally, the
sensor is biocompatible, indicating the potential applications for
the next generation of epidermal sensors
Secondary Chemical Cross-Linking to Improve Mechanical Properties in a Multifaceted Biocompatible Strain Sensor
A new conductive and transparent organohydrogel is developed
with
high stretchability, excellent mechanical, self-healing, antifreezing,
and adhesive properties. A simple one-pot polymerization method is
used to create polyacrylamide cross-linked through N,N′-methylenebis(acrylamide) (MBAA) and divinylbenzene
(DVB). The dual chemical cross-linked gel network is complemented
by several physical cross-links via hydrogen bonding and π–π
interaction. Multiple chemical and physical cross-links are used to
construct the gel network that allows toughness (171 kPa), low modulus
(≈45 kPa), excellent stretchability (>1100%), and self-healing
ability. The use of appropriate proportions of the water/glycerol
binary solvent system ensures efficient environment tolerance (−20
to 40 °C). Phytic acid is used as a conductive filler that provides
excellent conductivity and contributes to the physical cross-linking.
Dopamine is incorporated in the gel matrix, which endows excellent
adhesive property of the gel. The organohydrogel-based strain sensors
are developed with state-independent properties, highly linear dependence,
and excellent antifatigue performance (>100 cycles). Moreover,
during
the practical wearable sensing tests, human motions can be detected,
including speaking, smiling, and joint movement. Additionally, the
sensor is biocompatible, indicating the potential applications for
the next generation of epidermal sensors
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