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1.
Small ; 14(39): e1801724, 2018 09.
Article in English | MEDLINE | ID: mdl-30035853

ABSTRACT

Here, a spotlight is shown on aqueous microgel particles which exhibit a great potential for various biomedical applications such as drug delivery, cell imaging, and tissue engineering. Herein, different synthetic methods to develop microgels with desirable functionality and properties along with degradable strategies to ensure their renal clearance are briefly presented. A special focus is given on the ability of microgels to respond to various stimuli such as temperature, pH, redox potential, magnetic field, light, etc., which helps not only to adjust their physical and chemical properties, and degradability on demand, but also the release of encapsulated bioactive molecules and thus making them suitable for drug delivery. Furthermore, recent developments in using the functional microgels for cell imaging and tissue regeneration are reviewed. The results reviewed here encourage the development of a new class of microgels which are able to intelligently perform in a complex biological environment. Finally, various challenges and possibilities are discussed in order to achieve their successful clinical use in future.


Subject(s)
Gels/chemistry , Tissue Engineering/methods , Biocompatible Materials/chemistry , Drug Delivery Systems/methods , Polymers/chemistry
2.
Am J Physiol Endocrinol Metab ; 310(11): E1016-26, 2016 06 01.
Article in English | MEDLINE | ID: mdl-27117005

ABSTRACT

Long-term pancreatic cold ischemia contributes to decreased islet number and viability after isolation and culture, leading to poor islet transplantation outcome in patients with type 1 diabetes. In this study, we examined mechanisms of pancreatic cold preservation and rewarming-induced injury by interrogating the proapoptotic gene BBC3/Bbc3, also known as Puma (p53 upregulated modulator of apoptosis), using three experimental models: 1) bioluminescence imaging of isolated luciferase-transgenic ("Firefly") Lewis rat islets, 2) cold preservation of en bloc-harvested pancreata from Bbc3-knockout (KO) mice, and 3) cold preservation and rewarming of human pancreata and isolated islets. Cold preservation-mediated islet injury occurred during rewarming in "Firefly" islets. Silencing Bbc3 by transfecting Bbc3 siRNA into islets in vitro prior to cold preservation improved postpreservation mitochondrial viability. Cold preservation resulted in decreased postisolation islet yield in both wild-type and Bbc3 KO pancreata. However, after culture, the islet viability was significantly higher in Bbc3-KO islets, suggesting that different mechanisms are involved in islet damage/loss during isolation and culture. Furthermore, Bbc3-KO islets from cold-preserved pancreata showed reduced HMGB1 (high-mobility group box 1 protein) expression and decreased levels of 4-hydroxynonenal (4-HNE) protein adducts, which was indicative of reduced oxidative stress. During human islet isolation, BBC3 protein was upregulated in digested tissue from cold-preserved pancreata. Hypoxia in cold preservation increased BBC3 mRNA and protein in isolated human islets after rewarming in culture and reduced islet viability. These results demonstrated the involvement of BBC3/Bbc3 in cold preservation/rewarming-mediated islet injury, possibly through modulating HMGB1- and oxidative stress-mediated injury to islets.


Subject(s)
Apoptosis Regulatory Proteins/metabolism , Cell Survival/physiology , Cryopreservation/methods , Islets of Langerhans/injuries , Islets of Langerhans/physiopathology , Proto-Oncogene Proteins/metabolism , Rewarming/adverse effects , Animals , Cells, Cultured , Humans , Oxidative Stress/physiology , Rats , Rats, Inbred Lew
3.
Acta Radiol ; 56(7): 782-9, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25009279

ABSTRACT

BACKGROUND: Using hepatocyte-specific magnetic resonance imaging (MRI) contrast agents such as gadoxetate disodium, MRI can provide functional information regarding the patency of the cystic duct similar to hepatobiliary scintigraphy in addition to anatomic images. PURPOSE: To describe the gadoxetate disodium enhanced MR cholangiography (GDE-MRC) findings in patients with acute cholecystitis and to compare them with findings in patients without acute cholecystitis and with normal hepatobiliary scintigraphy. MATERIAL AND METHODS: This study was HIPAA compliant and institutional review board approved. Twenty-three patients (n = 14 diagnosed with acute calculous cholecystitis based on ultrasound [US] or computed tomography [CT]; n = 9 controls with normal hepatobiliary scintigraphy) were prospectively enrolled. All patients underwent GDE-MRC within 2 days of the US, CT, or hepatobiliary scintigraphy. GDE-MRC included axial gradient echo T1-weighted images before and 3, 10, 20, 30, and 60 min after injection of 10 mL of gadoxetate disodium. If excretion of contrast into the gallbladder was not noted at 60 min, intravenous morphine was administered (0.04 mg/kg) and images were acquired 30 min later. RESULTS: In all nine controls, gadoxetate disodium was excreted into the gallbladder within 60 min (7/9 in <30 min). Twelve out of 14 patients with acute cholecystitis completed the study. Six out of 12 (50%) patients demonstrated contrast in their gallbladder within 1 h of administration similar to the control group (2/6 in <30 min). In the remaining 6/12 patients, contrast was not present in the gallbladder within 1 h from injection. Following morphine augmentation, contrast was subsequently noted in the gallbladder in 2/6 patients. CONCLUSION: GDE-MRC can assess the patency of the cystic duct. Delayed (>60 min) or lack of filling of the gallbladder during GDE-MRC supports the diagnosis of acute cholecystitis. However, filling of the gallbladder with contrast in <60 min does not exclude the diagnosis of acute calculous cholecystitis.


Subject(s)
Cholangiopancreatography, Magnetic Resonance/methods , Cholecystitis, Acute/pathology , Cystic Duct/pathology , Gadolinium DTPA , Gallbladder/pathology , Image Enhancement/methods , Adult , Contrast Media , Female , Humans , Image Processing, Computer-Assisted/methods , Prospective Studies , Reproducibility of Results , Young Adult
4.
Am Heart J ; 168(6): 948-55, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25458660

ABSTRACT

BACKGROUND: Health care utilization patterns and associated costs of congenital heart disease (CHD) in young adulthood are not well understood. METHODS: California State Inpatient Databases 2005 to 2009 were used to conduct a retrospective study on inpatient admissions of CHD patients 10 to 29 years old (n = 7,419) and of all patients of the same age (n = 1,195,233). RESULTS: Compared with all patients, annual admission costs of CHD patients monotonically decreased, from $13.9 million at age 10 to 14 years to $7.2 million at age 25 to 29 years, which were due to lower costs per admission and somewhat fewer annual hospitalizations. Admissions from the emergency department in CHD patients increased with age regardless of insurance status: at age 25 to 29 years, 62% of admissions with public insurance, 43% with private insurance, and 78% with no insurance were admitted from the emergency department. Cardiac surgery, catheterization, and electrophysiologic study admissions decreased with age in CHD patients, whereas admissions due to arrhythmia and congestive heart failures became more prevalent. Results from multivariate linear regression in CHD patients showed that cardiac surgery was the most costly factor, associated with $29,543 more in costs per admission, followed by the use of a children's hospital, at $10,533. Factors predicting lower costs included female gender, low-complexity CHD, and shorter stay, all P < .001. CONCLUSIONS: Compared with adolescents, young adults with CHD use fewer resources because the natural history of CHD results in fewer surgical admissions and more frequent but less expensive medical admissions.


Subject(s)
Cardiac Surgical Procedures , Heart Defects, Congenital , Hospitalization , Practice Patterns, Physicians' , Adolescent , Adult , California/epidemiology , Cardiac Surgical Procedures/economics , Cardiac Surgical Procedures/statistics & numerical data , Cardiac Surgical Procedures/trends , Databases, Factual , Emergency Service, Hospital/economics , Female , Heart Defects, Congenital/economics , Heart Defects, Congenital/epidemiology , Heart Defects, Congenital/therapy , Hospital Charges/statistics & numerical data , Hospitalization/economics , Hospitalization/statistics & numerical data , Hospitalization/trends , Humans , Insurance Coverage , Male , Practice Patterns, Physicians'/economics , Practice Patterns, Physicians'/statistics & numerical data , Practice Patterns, Physicians'/trends , Retrospective Studies
5.
ACS Appl Mater Interfaces ; 16(9): 11860-11871, 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38410836

ABSTRACT

In this research, we report dextrin-based biodegradable microgels (PDXE MGs) having phosphate-based cross-linking units for slow release of urea and a potential P source to improve fertilization. PDXE MGs (∼200 nm) are synthesized by cross-linking the lauroyl-functionalized dextrin chains with sodium tripolyphosphate. The developed PDXE MGs exhibit high loading (∼10%) and encapsulation efficiency (∼88%) for urea. It is observed that functionalization of PDXE MGs with lauroyl chains slows down the release of urea (90% in ∼24 days) as compared to nonfunctionalized microgels (PDX MGs) (99% in ∼17 days) in water. Further studies of the developed formulation display that Urea@PDXE MGs significantly boost maize seed germination and overall plant growth as compared to pure urea fertilizer. Moreover, analysis of maize leaves obtained from plants treated with Urea@PDXE MGs reveals 3.5 ± 0.3% nitrogen content and 90 ± 0.7 mg/g chlorophyll content. These values are significantly higher than 1.4 ± 0.6% nitrogen content and 48 ± 0.05 mg/g chlorophyll content obtained by using bare urea. Further, acid phosphatase activity in roots is reduced upon treatment with PDXE MGs and Urea@PDXE MGs, suggesting the availability of P upon degradation of PDXE MGs by the amylase enzyme in soil. These experimental results present the developed microgel-based biodegradable formulation with a slow release feature as a potential candidate to move toward sustainable agriculture practices.


Subject(s)
Microgels , Fertilizers , Dextrins , Agriculture , Soil , Nitrogen , Urea , Zea mays , Chlorophyll
6.
BMJ Open Qual ; 13(2)2024 Apr 22.
Article in English | MEDLINE | ID: mdl-38649197

ABSTRACT

Three years after the start of the SARS-CoV-2 virus (COVID-19) pandemic, its effects continue to affect society and COVID-19 vaccination campaigns continue to be a topic of controversy and inconsistent practice. After experiencing spikes in COVID-19 cases, our University of California Davis Health Division of Hospital Medicine sought to understand the reasons underlying the low COVID-19 vaccination rates in our county and find approaches to improve the number of vaccinations among adults admitted to the inpatient setting. This quality improvement project aimed to increase COVID-19 primary and booster vaccine efforts through a multi-pronged approach of increased collaboration with specialised staff and optimisation of use of our electronic health record system.Our key interventions focused on developing a visual reminder of COVID-19 vaccine status using the functionality of our electronic medical record (EMR), standardising documentation of COVID-19 vaccine status and enhancing team-based vaccination discussions through team huddles and partnering with inpatient care coordinators. While our grassroots approach enhanced COVID-19 vaccination rates in the inpatient setting and had additional benefits such as increased collaboration among teams, system-level efforts often made a greater impact at our healthcare centre. For other institutions interested in increasing COVID-19 vaccination rates, our top three recommendations include integrating vaccination into pre-existing workflows, optimising EMR functionality and increasing vaccine accessibility in the inpatient setting.


Subject(s)
COVID-19 Vaccines , COVID-19 , Hospitalists , Quality Improvement , SARS-CoV-2 , Humans , COVID-19/prevention & control , COVID-19 Vaccines/therapeutic use , COVID-19 Vaccines/administration & dosage , Hospitalists/statistics & numerical data , Vaccination/statistics & numerical data , Vaccination/methods , Electronic Health Records/statistics & numerical data , California
7.
ACS Appl Bio Mater ; 7(2): 879-891, 2024 02 19.
Article in English | MEDLINE | ID: mdl-38323456

ABSTRACT

In this study, a self-healing, adhesive, and superabsorbent film made of gelatin, poly(acrylamide), and boric acid (GelAA) was successfully synthesized using a free radical reaction mechanism. The optimized film showed a remarkable 2865 ± 42% water absorptivity and also exhibited excellent self-healing behavior. The GelAA films were further loaded with silver nanoclusters (AgNCs) and ursodeoxycholic acid (UDC) (loading efficiency = 10%) to develop UDC/Ag/GelAA films. The loading of AgNCs in UDC/Ag/GelAA films helped in exhibiting 99.99 ± 0.01% antibacterial activity against both Gram-positive and Gram-negative bacteria, making them very effective against bacterial infections. Additionally, UDC/Ag/GelAA films had 77.19 ± 0.52% porosity and showed 90% of UDC release in 30 h, which helps in improving the cell proliferation. Our research provides an easy but highly effective process for synthesizing a hydrogel film, which is an intriguing choice for wound healing applications without the use of antibiotics.


Subject(s)
Acrylic Resins , Anti-Bacterial Agents , Anti-Infective Agents , Methylgalactosides , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Gelatin/pharmacology , Gram-Negative Bacteria , Gram-Positive Bacteria , Wound Healing
8.
Int J Biol Macromol ; 228: 323-332, 2023 Feb 15.
Article in English | MEDLINE | ID: mdl-36572087

ABSTRACT

To meet the growing food demand of increasing world population while reducing the harmful environmental effects of agrochemicals, development of smart nanoformulation is of prime importance. Herein, dual stimuli responsive alginate based microgels (OAlgDP MGs) (≈160 nm) are developed for controlled release of agrochemicals and soil remediation. These microgels are prepared using octyl amine functionalized alginate which is crosslinked by 3, 3'-dithiopropionohydrazide crosslinker providing both hydrazone and disulfide bonds in microgels network. OAlgDP MGs are further loaded with hydrophobic diuron herbicide displaying ≈85 % encapsulation efficiency. Sustained release of diuron is obtained in 2 mM GSH (≈100 % after 380 h) and at pH 5 (≈72 % after 240 h). Furthermore, OAlgDP MGs are nontoxic up to 150 µg/mL against HEK293T cells while their reduced form is capable of capturing the heavy metal ions (Cu2+ and Hg2+) showing the potential of the developed system for moving toward sustainable agriculture.


Subject(s)
Microgels , Humans , Microgels/chemistry , Diuron , Soil , Alginates/chemistry , Agrochemicals , HEK293 Cells
9.
Carbohydr Polym ; 313: 120893, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37182935

ABSTRACT

In this work, we report redox sensitive, 2,3-dihydroxybenzoic acid (DH) functionalized chitosan/stearic acid microgels (DH-ChSt MGs) for controlled delivery of insecticide and capturing of heavy metal ions. DH-ChSt MGs (≈146 nm) are prepared by disulfide crosslinking of SH functionalized chitosan and stearic acid rendering them biodegradable. DH-ChSt MGs exhibit high loading (≈8 %) and encapsulation (≈85 %) efficiency for imidacloprid insecticide, and offer its prolonged release (≈75 % after 133 h) under reducing conditions. Functionalization with DH provides enhanced foliar adhesion on pea leaves. DH-ChSt MGs also bind Fe3+ very efficiently due to the strong chelation of Fe3+ by DH, offering the opportunity of supplying Fe3+ nutrient for plant care. MTT assay results using different cells confirm that DH-ChSt MGs are nontoxic up to the experimental concentration of 120 µg/mL. Additionally, reduced DH-ChSt MGs having free thiol groups are also capable of binding heavy metal ions, thus presenting the reported formulation as a promising platform for agriculture application.


Subject(s)
Chitosan , Insecticides , Metals, Heavy , Microgels , Agriculture , Oxidation-Reduction
10.
Nanoscale ; 15(7): 3273-3283, 2023 Feb 16.
Article in English | MEDLINE | ID: mdl-36723053

ABSTRACT

Herein, we present disulfide crosslinked dextran/eudragit S-100 nanoparticles (DEEU NPs) (≈55 nm) for colorectal cancer treatment. These redox environment sensitive DEEU NPs are synthesized by simple oxidation of thiolated polymers in air. This approach allows avoiding the use of any additional chemical crosslinker. These DEEU NPs have high encapsulation efficiency for the doxorubicin (DOX) model drug (≈95%). The prepared DEEU NPs are redox sensitive owing to disulfide units and exhibit ≈80% DOX release in the reducing environment of GSH. Additionally, DOX-DEEU NPs display enhanced cytotoxicity for HCT116 cancer cells as compared to free DOX. Annexin V staining results also support the higher anticancer efficiency of DOX-DEEU NPs via induction of apoptosis. In vivo biodistribution results demonstrate that DEEU NPs can remain in the colon region for up to 24 hours. These results indicate that DEEU NPs can act as a promising platform for colorectal cancer treatment.


Subject(s)
Colorectal Neoplasms , Nanoparticles , Humans , Dextrans , Tissue Distribution , Doxorubicin/pharmacology , Drug Delivery Systems/methods , Oxidation-Reduction , Nanoparticles/therapeutic use , Disulfides , Colorectal Neoplasms/drug therapy
11.
Chem Commun (Camb) ; 59(79): 11819-11822, 2023 Oct 04.
Article in English | MEDLINE | ID: mdl-37721201

ABSTRACT

In the current study, we synthesized thiolated chitosan-stabilized gold-coated, gadolinium-doped hafnium oxide nanoparticles (CAuGH NPs) with the capability of acting as a multifunctional system to deliver anticancer drug doxorubicin (DOX), to enhance radiosensitization by ROS generation, and to provide magnetic resonance (MR) imaging contrast for biomedical applications.


Subject(s)
Chitosan , Nanoparticles , Precision Medicine , Gold , Doxorubicin/pharmacology , Magnetic Resonance Imaging , Contrast Media
12.
PLoS One ; 18(9): e0291472, 2023.
Article in English | MEDLINE | ID: mdl-37703271

ABSTRACT

PURPOSE: This study determined whether initiation of pharmacologic treatment was delayed for newly diagnosed osteoporosis patients during the COVID-19 pandemic. METHODS: 1,189 patients ≥50 years with newly diagnosed osteoporosis using dual-energy x-ray absorptiometry (DXA) screening at a single academic institution were included. Patients with previous osteoporosis were excluded. Patients diagnosed between March 1, 2018-January 31, 2020 (pre-pandemic cohort, n = 576) were compared to those diagnosed between March 1, 2020-January 31, 2022 (pandemic cohort, n = 613). Age, sex, race, ethnicity, ordering providers (primary vs specialty), and pharmacological agents were evaluated. Primary outcomes included proportion of patients prescribed therapy within 3 and 6-months of diagnosis, and mean time from diagnosis to treatment initiation. RESULTS: The pre-pandemic cohort had more White patients (74.3 vs 68.4%, p = .02) and no differences between remaining demographic variables. Only 40.5% of newly diagnosed patients initiated pharmacologic therapy within 6 months. Patients treated at 3-months (31.8 vs 35.4%, p = 0.19) and 6-months (37.8 vs 42.9, p = 0.08) were comparable between cohorts (47.2 vs 50.2% p = 0.30). Mean time from diagnosis to treatment initiation was similar (46 vs 45 days, p = 0.72). There were no treatment differences based on gender, race, or ethnicity or between ordering providers (65.1 vs 57.4% primary care, p = 0.08). Bisphosphonates were most often prescribed in both cohorts (89% vs 82.1%). CONCLUSIONS: This is the first study assessing COVID-19's impact on pharmacologic treatment of newly diagnosed osteoporosis. 40.5% of newly diagnosed patients were treated pharmacologically within six months of diagnosis, and the pandemic did not significantly affect treatment rates.


Subject(s)
COVID-19 , Medicine , Osteoporosis , Humans , Pandemics , Absorptiometry, Photon , Osteoporosis/diagnosis , Osteoporosis/drug therapy , Osteoporosis/epidemiology
13.
Int J Biol Macromol ; 247: 125606, 2023 Aug 30.
Article in English | MEDLINE | ID: mdl-37406894

ABSTRACT

Nature-derived or biologically encouraged hydrogels have attracted considerable interest in numerous biomedical applications owing to their multidimensional utility and effectiveness. The internal architecture of a hydrogel network, the chemistry of the raw materials involved, interaction across the interface of counter ions, and the ability to mimic the extracellular matrix (ECM) govern the clinical efficacy of the designed hydrogels. This review focuses on the mechanistic viewpoint of different biologically driven/inspired biomacromolecules that encourages the architectural development of hydrogel networks. In addition, the advantage of hydrogels by mimicking the ECM and the significance of the raw material selection as an indicator of bioinertness is deeply elaborated in the review. Furthermore, the article reviews and describes the application of polysaccharides, proteins, and synthetic polymer-based multimodal hydrogels inspired by or derived from nature in different biomedical areas. The review discusses the challenges and opportunities in biomaterials along with future prospects in terms of their applications in biodevices or functional components for human health issues. This review provides information on the strategy and inspiration from nature that can be used to develop a link between multimodal hydrogels as the main frame and its utility in biomedical applications as the primary target.


Subject(s)
Hydrogels , Polymers , Humans , Hydrogels/chemistry , Polymers/chemistry , Proteins/therapeutic use , Biocompatible Materials/chemistry , Polysaccharides/chemistry
14.
J Magn Reson Imaging ; 35(1): 125-31, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21953793

ABSTRACT

PURPOSE: To retrospectively determine the incremental value of diffusion-weighted MR-imaging (DW-MRI) to T2-weighted (T2w) images in diagnosis of internal fistulas (IFs) and sinus tracts (STs). MATERIALS AND METHODS: Fourteen patients with 25 IFs and STs arising from the small bowel (20), colon (4) and biliary tract (1) were included. Two independent observers reviewed T2w images, T2w+DW-MRI images and T2w+contrast enhanced T1-weighted (CE T1w) images at three sessions to detect IF/ST based on a confidence scale of five. Sensitivity and confidence score of each session was compared. RESULTS: 10/25 (40%) and 9/25 (36%) IFs and STs were detected on T2w images by observer 1 and 2, respectively. Both observers detected 19/25 (76%) and 24/25(96%) IFs and STs on T2w+DW-MRI and T2w+CE T1w images, respectively. Detection rate and confidence score improved significantly by combining T2w images with DW-MRI or CE T1w images (reader 1 + 2: P ≤ 0.01). There was no significant difference between the IF/ST detection rate of T2w+DW-MRI and T2w+CE T1 image combinations. Confidence scores with T2w+CE T1w images were significantly greater than DW-MRI+T2w images (reader 1:P = 0.01; reader 2: P = 0.03). CONCLUSION: DW-MRI showed additional value to T2w imaging for diagnosis of IF and ST. DW-MRI can be a useful adjunct, especially for patients with renal failure.


Subject(s)
Diffusion Magnetic Resonance Imaging/methods , Fistula/diagnosis , Magnetic Resonance Imaging/methods , Abdomen/pathology , Adolescent , Adult , Aged , Aged, 80 and over , Contrast Media/pharmacology , Female , Humans , Intestinal Fistula/pathology , Male , Middle Aged , Observer Variation , Reproducibility of Results , Retrospective Studies , Sensitivity and Specificity
15.
ACS Biomater Sci Eng ; 8(6): 2281-2306, 2022 06 13.
Article in English | MEDLINE | ID: mdl-35513349

ABSTRACT

Designing novel systems for efficient cancer treatment and improving the quality of life for patients is a prime requirement in the healthcare sector. In this regard, theranostics have recently emerged as a unique platform, which combines the benefits of both diagnosis and therapeutics delivery. Theranostics have the desired contrast agent and the drugs combined in a single carrier, thus providing the opportunity for real-time imaging to monitor the therapy results. This helps in reducing the hazards related to treatment overdose or underdose and gives the possibility of personalized therapy. Polysaccharides, as natural biomolecules, have been widely explored to develop theranostics, as they act as a matrix for simultaneously loading both contrast agents and drugs for their utility in drug delivery and imaging. Additionally, their remarkable physicochemical attributes (biodegradability, satisfactory safety profile, abundance, and diversity in functionality and charge) can be tuned via postmodification, which offers numerous possibilities to develop theranostics with desired characteristics. Hence, we provide an overview of recent advances in polysaccharide matrix-based theranostics for drug delivery combined with magnetic resonance imaging, computed tomography, positron emission tomography, single photon emission computed tomography, and ultrasound imaging. Herein, we also summarize the toxicity assessment of polysaccharides, associated contrast agents, and nanotoxicity along with the challenges and future research directions.


Subject(s)
Neoplasms , Precision Medicine , Contrast Media/therapeutic use , Humans , Magnetic Resonance Imaging , Neoplasms/diagnostic imaging , Neoplasms/drug therapy , Pharmaceutical Preparations , Polysaccharides/therapeutic use , Quality of Life
16.
Carbohydr Polym ; 294: 119833, 2022 Oct 15.
Article in English | MEDLINE | ID: mdl-35868778

ABSTRACT

Herein, redox responsive chitosan/stearic acid nanoparticles (CSSA NPs) (≈200 nm) are developed for dual drug delivery. These degradable nanoparticles are prepared based on disulfide (SS) crosslinking chemistry avoiding the use of any external crosslinking agent. CSSA NPs are further loaded with both DOX (hydrophilic) and curcumin (hydrophobic) drugs with ≈86 % and ≈82 % encapsulation efficiency respectively. This approach of combining anticancer therapeutics having different mode of anticancer action allows to develop systems for cancer therapy with enhanced efficacy. In vitro drug release experiments clearly exhibit the low leakage of drug under physiological conditions while ≈98 % DOX and ≈96 % curcumin is released after 136 h under GSH reducing conditions. The cytotoxicity experiments against HCT116 cells demonstrate higher cytotoxicity of dual drug loaded CSSA NPs. In vivo biodistribution experiments with c57bl/6j mice confirms the retention of CSSA NPs in the colon area up to 24 h exhibiting their potential for colorectal cancer therapy.


Subject(s)
Chitosan , Colorectal Neoplasms , Curcumin , Nanoparticles , Animals , Chitosan/chemistry , Colorectal Neoplasms/drug therapy , Curcumin/chemistry , Disulfides/chemistry , Doxorubicin/pharmacology , Doxorubicin/therapeutic use , Drug Carriers/chemistry , Drug Delivery Systems , Drug Liberation , Mice , Nanoparticles/chemistry , Stearic Acids , Tissue Distribution
17.
Biomater Adv ; 143: 213184, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36371969

ABSTRACT

Herein, we report redox responsive, colon cancer targeting poly(allylamine) (PA)/eudragit S-100 (EU) nanoparticles (PAEU NPs) (≈59 nm). These disulfide crosslinked PAEU NPs are developed via air oxidation of thiolated PA and thiolated EU, eliminating the need of any external crosslinking agent for dual drug delivery. PAEU NPs can effectively encapsulate both hydrophilic doxorubicin (DOX) and hydrophobic curcumin (Cur) drug with ≈85 % and ≈97 % encapsulation efficiency respectively. Here, the combination of drugs having different anticancer mechanism offers the possibility of developing nanosystem with enhanced anticancer efficacy. The developed PAEU NPs show good colloidal stability and low drug release under physiological conditions, while high DOX (≈98 %) and Cur (≈93 %) release is observed in reducing environment (10 mM GSH). Further, DOX and Cur loaded PAEU NPs exhibit higher cancer cell killing efficiency as compared to individual free drugs. In vivo biodistribution studies with Balb/C mice display the retention of PAEU NPs in the colon region up to 24 h presenting the developed approach as an efficient way for colorectal cancer therapy.


Subject(s)
Allylamine , Colorectal Neoplasms , Curcumin , Nanoparticles , Mice , Animals , Tissue Distribution , Doxorubicin/therapeutic use , Oxidation-Reduction , Colorectal Neoplasms/drug therapy
18.
Int J Biol Macromol ; 219: 353-365, 2022 Oct 31.
Article in English | MEDLINE | ID: mdl-35926676

ABSTRACT

Herein, we report the synthesis and characterization of gelatin/κ-carrageenan crosslinked polyacrylic acid hydrogel (GT-CAG-cl-polyAA) and graphene oxide incorporated hydrogel nanocomposite (GOHNC) through a free radical crosslinking pathway. Under optimized reaction conditions, GT-CAG-cl-polyAA displayed 486 % maximum swelling percentage. TEM image depicted wrinkled silk veil wave-type surface morphology of graphene oxide (GO), whereas, the SEM analysis indicated the porous nature of the GT-CAG-cl-polyAA and GOHNC capable of accumulating a large number of water/dye molecules. GT-CAG-cl-polyAA exhibited 96.11 % and 82.16 % dye removal potential for the adsorption of methylene blue (MB) and coomassie brilliant blue (CB), respectively under optimized conditions. GOHNC enhanced the % dye removal efficiency (98.39 % for MB and 94.50 % for CB). The maximum adsorption capacity of GOHNC for the removal of CB and MB was 312.7 mg/g and 94.9 mg/g, respectively. The adsorption of CB and MB exhibited best fitting with Flory-Huggins adsorption isotherms data. The negative values of ΔG° and positive values of ΔS° which were obtained from the adsorption isotherm plot suggested the thermodynamic feasibility of the adsorption. Also, the samples were reusable for up to five consecutive cycles without any degradation and hence suggested a considerable pathway for the separation of textile dyes.


Subject(s)
Water Pollutants, Chemical , Water Purification , Adsorption , Carrageenan , Coloring Agents , Gelatin , Graphite , Hydrogels , Kinetics , Methylene Blue , Rosaniline Dyes , Silk , Water
19.
Carbohydr Polym ; 296: 119964, 2022 Nov 15.
Article in English | MEDLINE | ID: mdl-36088004

ABSTRACT

3D printed hydrogels have emerged as a novel tissue engineering and regeneration platform due to their ability to provide a suitable environment for cell growth. To obtain a well-defined scaffold with good post-printing shape fidelity, a proper hydrogel ink formulation plays a crucial role. In this regard, alginate has received booming interest owing to its biocompatibility, biodegradability, easy functionalization, and fast gelling behavior. Hence, this review highlights the significance of alginate-based hydrogel inks for fabricating 3D printed scaffolds for bone and cartilage regeneration. Herein, we discuss the fundamentals of direct extrusion 3D bioprinting method and provide a comprehensive overview of various alginate-based hydrogel ink formulations that have been used so far. We also summarize the requirements of hydrogel inks and 3D printed scaffolds to achieve similarity to the native tissue environment. Finally, we discuss the challenges, and research directions relevant for future clinical translation.


Subject(s)
Bioprinting , Alginates , Excipients , Hydrogels , Ink , Printing, Three-Dimensional , Tissue Engineering , Tissue Scaffolds
20.
J Magn Reson Imaging ; 34(4): 956-61, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21928309

ABSTRACT

PURPOSE: To evaluate feasibility of high-resolution, high-field ex vivo prostate magnetic resonance imaging (MRI) as an aid to guide pathologists' examination and develop in vivo MRI methods. MATERIALS AND METHODS: Unfixed excised prostatectomy specimens (n = 9) were obtained and imaged immediately after radical prostatectomy under an Institutional Review Board-approved protocol. High-resolution T2-weighted (T2W) MRI of specimens were acquired with a Bruker 9.4 T scanner to correlate with whole-mount histology. Additionally, T2 and apparent diffusion coefficient (ADC) maps were generated. RESULTS: By visual inspection of the nine prostate specimens imaged, high-resolution T2W MRI showed improved anatomical detail compared to published low-resolution images acquired at 4 T as published by other investigators. Benign prostatic hyperplasia, adenocarcinomas, curvilinear duct architecture distortion due to adenocarcinomas, and normal radial duct distribution were readily identified. T2 was ≈10 msec longer (P < 0.03) and the ADC was ≈1.4 times larger (P < 0.002) in the normal peripheral zone compared to the peripheral zone with prostate cancer. CONCLUSION: Differences in T2 and ADC between benign and malignant tissue are consistent with in vivo data. High-resolution, high-field MRI has the potential to improve the detection and identification of prostate structures. The protocols and techniques developed in this study could augment routine pathological analysis of surgical specimens and guide treatment of prostate cancer patients.


Subject(s)
Image Enhancement/methods , Magnetic Resonance Imaging/methods , Prostate/pathology , Prostatic Neoplasms/diagnosis , Aged , Aged, 80 and over , Biopsy, Needle , Humans , Immunohistochemistry , Male , Middle Aged , Prospective Studies , Prostatectomy/methods , Prostatic Neoplasms/surgery , Sensitivity and Specificity , Statistics, Nonparametric , Tissue Culture Techniques
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