28 research outputs found
Facile Fabrication of Lubricant-Infused Wrinkling Surface for Preventing Thrombus Formation and Infection
Tunable backbone-degradable robust tissue adhesives via in situ radical ring-opening polymerization
Abstract Adhesives with both robust adhesion and tunable degradability are clinically and ecologically vital, but their fabrication remains a formidable challenge. Here we propose an in situ radical ring-opening polymerization (rROP) strategy to design a backbone-degradable robust adhesive (BDRA) in physiological environment. The hydrophobic cyclic ketene acetal and hydrophilic acrylate monomer mixture of the BDRA precursor allows it to effectively wet and penetrate substrates, subsequently forming a deep covalently interpenetrating network with a degradable backbone via redox-initiated in situ rROP. The resulting BDRAs show good adhesion strength on diverse materials and tissues (e.g., wet bone >16 MPa, and porcine skin >150 kPa), higher than that of commercial cyanoacrylate superglue (~4 MPa and 56 kPa). Moreover, the BDRAs have enhanced tunable degradability, mechanical modulus (100 kPa-10 GPa) and setting time (seconds-hours), and have good biocompatibility in vitro and in vivo. This family of BDRAs expands the scope of medical adhesive applications and offers an easy and environmentally friendly approach for engineering
Optimization of Alkyl Side Chain Length in Polyimide for Gate Dielectrics to Achieve High Mobility and Outstanding Operational Stability in Organic Transistors
Alkyl chain modification strategies in both organic semiconductors
and inorganic dielectrics play a crucial role in improving the performance
of organic thin-film transistors (OTFTs). Polyimide (PI) and its derivatives
have received extensive attention as dielectrics for application in
OTFTs because of flexibility, high-temperature resistance, and low
cost. However, low-temperature solution processing PI-based gate dielectric
for flexible OTFTs with high mobility, low operating voltage, and
high operational stability remains an enormous challenge. Furthermore,
even though di-n-decyldinaphtho[2,3-b:2′,3′-f]thieno[3,2-b]thiophene (C10-DNTT) is known to have very
high mobility as an air-stable and high-performance organic semiconductor,
the C10-DNTT-based TFTs on the PI gate dielectrics still
showed relatively low mobility. Here, inspired by alkyl side chain
engineering, we design and synthesize a series of PI materials with
different alkyl side chain lengths and systematically investigate
the PI surface properties and the evolution of organic semiconductor
morphology deposited on PI surfaces during the variation of alkyl
side chain lengths. It is found that the alkyl side chain length has
a critical influence on the PI surface properties, as well as the
grain size and molecular orientation of semiconductors. Good field-effect
characteristics are obtained with high mobilities (up to 1.05 and
5.22 cm2/Vs, which are some of the best values reported
to date), relatively low operating voltage, hysteresis-free behavior,
and high operational stability in OTFTs. These results suggest that
the strategy of optimizing alkyl side-chain lengths opens up a new
research avenue for tuning semiconductor growth to enable high mobility
and outstanding operational stability of PI-based OTFTs
Degradable Nanohydroxyapatite-Reinforced Superglue for Rapid Bone Fixation and Promoted Osteogenesis
Bone glue with robust adhesion is
crucial for treating
complicated
bone fractures, but it remains a formidable challenge to develop a
“true” bone glue with high adhesion strength, degradability,
bioactivity, and satisfactory operation time in clinical scenarios.
Herein, inspired by the hydroxyapatite and collagen matrix composition
of natural bone, we constructed a nanohydroxyapatite (nHAP) reinforced
osteogenic backbone-degradable superglue (O-BDSG) by in situ radical ring-opening polymerization. nHAP significantly enhances
adhesive cohesion by synergistically acting as noncovalent connectors
between polymer chains and increasing the molecular weight of the
polymer matrix. Moreover, nHAP endows the glue with bioactivity to
promote osteogenesis. The as-prepared glue presented a 9.79 MPa flexural
adhesion strength for bone, 4.7 times that without nHAP, and significantly
surpassed commercial cyanoacrylate (0.64 MPa). O-BDSG exhibited degradability
with 51% mass loss after 6 months of implantation. In vivo critical defect and tibia fracture models demonstrated the promoted
osteogenesis of the O-BDSG, with a regenerated bone volume of 75%
and mechanical function restoration to 94% of the native tibia after
8 weeks. The glue can be flexibly adapted to clinical scenarios with
a curing time window of about 3 min. This work shows promising prospects
for clinical application in orthopedic surgery and may inspire the
design and development of bone adhesives
Facile Fabrication of Lubricant-Infused Wrinkling Surface for Preventing Thrombus Formation and Infection
Despite
the advanced modern biotechniques, thrombosis and bacterial infection
of biomedical devices remain common complications that are associated
with morbidity and mortality. Most antifouling surfaces are in solid
form and cannot simultaneously fulfill the requirements for antithrombosis
and antibacterial efficacy. In this work, we present a facile strategy
to fabricate a slippery surface. This surface is created by combining
photografting polymerization with osmotically driven wrinkling that
can generate a coarse morphology, and followed by infusing with fluorocarbon
liquid. The lubricant-infused wrinkling slippery surface can greatly
prevent protein attachment, reduce platelet adhesion, and suppress
thrombus formation in vitro. Furthermore, <i>E. coli</i> and <i>S. aureus</i> attachment on the slippery surfaces
is reduced by ∼98.8% and ∼96.9% after 24 h incubation,
relative to poly(styrene-<i>b</i>-isobutylene-<i>b</i>-styrene) (SIBS) references. This slippery surface is biocompatible
and has no toxicity to L929 cells. This surface-coating strategy that
effectively reduces thrombosis and the incidence of infection will
greatly decrease healthcare costs
Antibacterial and Hemocompatibility Switchable Polypropylene Nonwoven Fabric Membrane Surface
In
this article, a facile approach to fabricate a biofunctional polypropylene
nonwoven fabric membrane (PP NWF) with a switchable surface from antibacterial
property to hemocompatibility is presented. In the first step, a cationic
carboxybetaine ester monomer, [(2-(methacryboxy) ethyl)]-<i>N</i>,<i>N</i>-dimethylamino-ethylammonium bromide, methyl ester
(CABA-1-ester) was synthesized. Subsequently, this monomer was introduced
on the PP NWF surface via plasma pretreatment and a UV-induced graft
polymerization technique. Finally, a switchable surface from antibacterial
property to hemocompatibility was easily realized by hydrolysis of
poly(CABA-1-ester) moieties on the PP NWF surface under mild conditions.
Surface hydrolysis behaviors under different pH conditions were investigated.
These PP NWFs grafted with poly(CABA-1-ester) segments can cause significant
suppression of S. aureus proliferation;
after hydrolysis, these surfaces covered by poly[(2-(methacryloxy)
ethyl)] carboxybetaine (poly(CABA)) chains exhibited obvious reduction
in protein adsorption and platelet adhesion, and remarkably enhanced
antithrombotic properties. This strategy demonstrated that a switchable
PP NWF surface from antibacterial property to hemocompatibility was
easily developed by plasma pretreatment and UV-induced surface graft
polymerization and that this surface may become an attractive platform
for a range of biomedical applications
Degradable Nanohydroxyapatite-Reinforced Superglue for Rapid Bone Fixation and Promoted Osteogenesis
Bone glue with robust adhesion is
crucial for treating
complicated
bone fractures, but it remains a formidable challenge to develop a
“true” bone glue with high adhesion strength, degradability,
bioactivity, and satisfactory operation time in clinical scenarios.
Herein, inspired by the hydroxyapatite and collagen matrix composition
of natural bone, we constructed a nanohydroxyapatite (nHAP) reinforced
osteogenic backbone-degradable superglue (O-BDSG) by in situ radical ring-opening polymerization. nHAP significantly enhances
adhesive cohesion by synergistically acting as noncovalent connectors
between polymer chains and increasing the molecular weight of the
polymer matrix. Moreover, nHAP endows the glue with bioactivity to
promote osteogenesis. The as-prepared glue presented a 9.79 MPa flexural
adhesion strength for bone, 4.7 times that without nHAP, and significantly
surpassed commercial cyanoacrylate (0.64 MPa). O-BDSG exhibited degradability
with 51% mass loss after 6 months of implantation. In vivo critical defect and tibia fracture models demonstrated the promoted
osteogenesis of the O-BDSG, with a regenerated bone volume of 75%
and mechanical function restoration to 94% of the native tibia after
8 weeks. The glue can be flexibly adapted to clinical scenarios with
a curing time window of about 3 min. This work shows promising prospects
for clinical application in orthopedic surgery and may inspire the
design and development of bone adhesives
Liquid-Infused Poly(styrene‑<i>b</i>‑isobutylene‑<i>b</i>‑styrene) Microfiber Coating Prevents Bacterial Attachment and Thrombosis
Infection
and thrombosis associated with medical implants cause significant
morbidity and mortality worldwide. As we know, current technologies
to prevent infection and thrombosis may cause severe side effects.
To overcome these complications without using antimicrobial and anticoagulant
drugs, we attempt to prepare a liquid-infused poly(styrene-<i>b</i>-isobutylene-<i>b</i>-styrene) (SIBS) microfiber
coating, which can be directly coated onto medical devices. Notably,
the SIBS microfiber was fabricated through solution blow spinning.
Compared to electrospinning, the solution blow spinning method is
faster and less expensive, and it is easy to spray fibers onto different
targets. The lubricating liquids then wick into and strongly adhere
the microfiber coating. These slippery coatings can effectively suppress
blood cell adhesion, reduce hemolysis, and inhibit blood coagulation
in vitro. In addition, <i>Pseudomonas aeruginosa</i> (<i>P. aeruginosa</i>) on the lubricant infused coatings slides
readily, and no visible residue is left after tilting. We furthermore
confirm that the lubricants have no effects on bacterial growth. The
slippery coatings are also not cytotoxic to L929 cells. This liquid-infused
SIBS microfiber coating could reduce the infection and thrombosis
of medical devices, thus benefiting human health
Functionalization of Polypropylene with Chiral Monomer for Improving Hemocompatibility
Polypropylene (PP) is one of the most commonly used plastics because of its low density, outstanding mechanical properties, and low cost. However, its drawbacks such as low surface energy, poor dyeability, lack of chemical functionalities, and poor compatibility with polar polymers and inorganic materials, have restricted the application of PP. To expand its application in biomedical materials, functionalization is considered to be the most effective way. In this study, PP was functionalized with a chiral monomer, (S)-1-acryloylpyrrolidine-2-carboxylic acid ((S)-APCA), by free-radical grafting in the solid phase. The grafting degree of PP-g-APCA was determined by chemical titration method, and the chemical structure of functionalized PP was characterized by FTIR spectroscopy, which confirmed that the chiral monomer (S)-APCA was successfully grafted onto PP. Static water contact angle results suggested that the surface hydrophilicity of PP was significantly improved by solid phase grafting and assistance of surface water treatment. Protein adsorption and platelet adhesion results showed that hemocompatibility of PP was greatly improved by grafting the chiral monomer