We have investigated the antitumor functions and mechanisms of 1,2-naphthoquinone-2-thiosemicarbazone (NQTS) and its metal complexes (Cu
2+, Pd
2+, and Ni
2+) against MCF-7 human breast cancer cells. ...The cells were dosed with these complexes at varying concentrations, and cell viability was measured by a sulforhodamine B (SRB) method. To study mechanisms of action, the complexes were incubated with topoisomerase II (topo II) and supercoiled DNA, linear DNA, nicked open DNA, and relaxed DNA were detected by agarose gel electrophoresis. The results revealed that these complexes are effective antitumor chemicals in inhibiting MCF-7 cell growth, with Ni-NQTS being the most effective among the complexes studied. Our data also indicated that Ni-NQTS is more effective than the commercial antitumor drug, etoposide, based on IC
50 values. The mechanistic study of action showed that metal complexes of NQTS, NQ, and NQTS can only stabilize the single-strand nicked DNA, but not double-strand breakage intermediates. In addition, metal derivatives of these ligands, but not the parent NQ and NQTS, exerted an antagonizing effect on topoisomerase II activity. In summary, chemicals with or without metal derivatives might possess different chemical–topoisomerase II–DNA interactions.
Extracellular vesicles (EVs) have potential in disease treatment since they can be loaded with therapeutic molecules and engineered for retention by specific tissues. However, questions remain on ...optimal dosing, administration and pharmacokinetics. Previous studies have addressed biodistribution and pharmacokinetics in rodents, but little evidence is available for larger animals. Here, we investigated the pharmacokinetics and biodistribution of Expi293F‐derived EVs labelled with a highly sensitive nanoluciferase reporter (palmGRET) in a non‐human primate model (Macaca nemestrina), comparing intravenous (IV) and intranasal (IN) administration over a 125‐fold dose range. We report that EVs administered IV had longer circulation times in plasma than previously reported in mice and were detectable in cerebrospinal fluid after 30–60 min. EV association with peripheral blood mononuclear cells, especially B‐cells, was observed as early as 1‐min post‐administration. EVs were detected in liver and spleen within 1 h of IV administration. However, IN delivery was minimal, suggesting that pretreatment approaches may be needed in large animals. Furthermore, EV circulation times strongly decreased after repeated IV administration, possibly due to immune responses and with clear implications for xenogeneic EV‐based therapeutics. We hope that our findings from this baseline study in macaques will help to inform future research and therapeutic development of EVs.
A method for simultaneous determination of polyamines and catecholamines in cell extracts by micellar electrokinetic capillary chromatography with UV detection at 254
nm was established at the first ...time. The polyamines (putrescine, spermidine and spermine) and catecholamines (dopamine, serotonin, norepinephrine and epinephrine) were extracted from PC-12 cells and were derivatized with 6-aminoquinolyl-
N-hydroxysuccinimidyl carbamate. Different derivatization conditions such as temperature, ratio of derivatization reagents and incubation time were investigated to find the best reaction condition which gave the highest detection sensitivity for polyamines and catecholamines. The influence of running buffer and additives on the separation such as pH, sodium dodecyl sulfate (SDS) concentrations and various additives was also investigated. Separation was achieved within 20
min with good repeatability in a 100
mM boric acid buffer containing 10
mM SDS and 10
mM 18-crown-6 at a pH of 9.5. The detection limit ranged from 1.0×10
−7 to 9.0×10
−7
M, which is sufficient for determination of polyamines and catecholamines in many cell extracts. This technique can be easily applied to polyamine-related anticancer drug studies or clinical follow-ups after each dosage of these anticancer drugs, since these drugs not only have great inhibition on polyamine levels in blood, but also have a large influence on catecholamine levels in blood.
Sugar-based biopolymers have been recognized as attractive materials to develop macromolecule- and nanoparticle-based cancer imaging and therapy. However, traditional biopolymer-based imaging ...approaches rely on the use of synthetic or isotopic labelling, and because of it, clinical translation often is hindered. Recently, a novel MRI technology, chemical exchange saturation transfer (CEST), has emerged, which allows the exploitation of sugar-based biopolymers as MR imaging agents by their hydroxyl protons-rich nature. In the article, we reviewed recent studies on the topic of CEST MRI detection of sugar-based biopolymers. The CEST MRI property of each biopolymer was briefly introduced, followed by the pre-clinical and clinical applications. The findings of these preliminary studies imply the enormous potential of CEST detectable sugar-based biopolymers in developing highly sensitive and translatable molecular imaging agents and constructing image-guided biopolymer-based drug delivery systems.
Among the strategies used for enhancement of tumour retention of imaging agents or anticancer drugs is the rational design of probes that undergo a tumour-specific enzymatic reaction preventing them ...from being pumped out of the cell. Here, the anticancer agent olsalazine (Olsa) was conjugated to the cell-penetrating peptide RVRR. Taking advantage of a biologically compatible condensation reaction, single Olsa-RVRR molecules were self-assembled into large intracellular nanoparticles by the tumour-associated enzyme furin. Both Olsa-RVRR and Olsa nanoparticles were readily detected with chemical exchange saturation transfer magnetic resonance imaging by virtue of exchangeable Olsa hydroxyl protons. In vivo studies using HCT116 and LoVo murine xenografts showed that the OlsaCEST signal and anti-tumour therapeutic effect were 6.5- and 5.2-fold increased, respectively, compared to Olsa without RVRR, with an excellent 'theranostic correlation' (R
= 0.97) between the imaging signal and therapeutic response (normalized tumour size). This furin-targeted, magnetic resonance imaging-detectable platform has potential for imaging tumour aggressiveness, drug accumulation and therapeutic response.
To extract guanidinium (Guan) and amide CEST on the human brain at 3 T MRI with the high spectral resolution (HSR) CEST combined with the polynomial Lorentzian line-shape fitting (PLOF).
Continuous ...wave (cw) turbo spin-echo (TSE) CEST was implemented to obtain the optimum saturation parameters. Both Guan and amide CEST peaks were extracted and quantified using the PLOF method. The NMR spectra on the egg white phantoms were acquired to reveal the fitting range and the contributions to the amide and GuanCEST. Two types of CEST approaches, including cw gradient- and spin-echo (cwGRASE) and steady state EPI (ssEPI), were implemented to acquire multi-slice HSR-CEST.
GuanCEST can be extracted with the PLOF method at 3 T, and the optimum
was determined for GuanCEST in white matter (WM) and 1.0 μT in gray matter (GM). The optimum B
= 0.8-1 μT was found for amideCEST. AmideCEST is lower in both WM and GM collected with ssEPI compared to those by cwGRASE (ssEPI = 1.27-1.63%; cwGRASE = 2.19-2.25%). The coefficients of variation (COV) of the amide and Guan CEST in both WM and GM for ssEPI (COV: 28.6-33.4%) are significantly higher than those of cwGRASE (COV: 8.6-18.8%). Completely different WM/GM contrasts for Guan and amide CEST were observed between ssEPI and cwGRASE. The amideCEST was found to have originated from the unstructured amide protons as suggested by the NMR spectrum of the unfolded proteins in egg white.
Guan and amide CEST mapping can be achieved by the HSR-CEST at 3 T combing with the PLOF method.
Purpose
Most existing non‐contrast‐enhanced methods for abdominal MR arteriography rely on a spatially selective inversion (SSI) pulse with a delay to null both static tissue and venous blood, and ...are limited to small spatial coverage due to the sensitivity to slow arterial inflow. Velocity‐selective inversion (VSI) based approach has been shown to preserve the arterial blood inside the imaging volume at 1.5 T. Recently, velocity‐selective saturation (VSS) pulse trains were applied to suppress the static tissue and have been combined with SSI pulses for cerebral MR arteriography at 3 T. The aim of this study is to construct an abdominal MRA protocol with large spatial coverage at 3 T using advanced velocity‐selective pulse trains.
Methods
Multiple velocity‐selective MRA protocols with different sequence modules and 3D acquisition methods were evaluated. Sequences using VSS only as well as SSI+VSS and VSI+VSS preparations were then compared among a group of healthy young and middle‐aged volunteers. Using MRA without any preparations as reference, relative signal ratios and relative contrast ratios of different vascular segments were quantitatively analyzed.
Results
Both SSI+VSS and VSI+VSS arteriograms achieved high artery‐to‐tissue and artery‐to‐vein relative contrast ratios above aortic bifurcation. The SSI+VSS sequence yielded lower signal at the bilateral iliac arteries than VSI+VSS, reflecting the benefit of the VSI preparation for imaging the distal branches.
Conclusion
The feasibility of noncontrast 3D MR abdominal arteriography was demonstrated on healthy volunteers using a combination of VSS pulse trains and SSI or VSI pulse.
Gadolinium (Gd)-based compounds and materials are the most commonly used magnetic resonance imaging (MRI) contrast agents in the clinic; however, safety concerns associated with their toxicities in ...the free ionic form have promoted the development of new generations of metal-free contrast agents. Here we report a supramolecular strategy to convert an FDA-approved anticancer drug, Pemetrexed (Pem), to a molecular hydrogelator with inherent chemical exchange saturation transfer (CEST) MRI signals. The rationally designed drug–peptide conjugate can spontaneously associate into filamentous assemblies under physiological conditions and consequently form theranostic supramolecular hydrogels for injectable delivery. We demonstrated that the local delivery and distribution of Pem–peptide nanofiber hydrogels can be directly assessed using CEST MRI in a mouse glioma model. Our work lays out the foundation for the development of drug-constructed theranostic supramolecular materials with an inherent CEST MRI signal that enables noninvasive monitoring of their in vivo distribution and drug release.
Intracerebral hemorrhage (ICH) remains the most lethal type of stroke, and effective clinical therapies that can speed up hematoma resolution after ICH are still lacking. While the beneficial effects ...of IL-10 on ICH recovery have been demonstrated, the clinical translation of IL-10 requires effective delivery methods by which sufficient IL-10 can be delivered to ICH-affected regions in the brain. Here we report the use of a phosphatidylserine (PS) liposome (PSL)-based nanoparticle system for microglia/macrophage-targeted delivery of IL-10 in ICH. We first prepared IL-10-conjugated PSL (PSL-IL10) and characterized their immunomodulating effects in vitro. Then we evaluated the therapeutic effects, including hematoma absorption, short-term outcomes, and neuroinflammation, of intranasally administered PSL-IL10 (3 μg IL-10 per mouse, 2 h post-ICH) in a collagenase-induced ICH mouse model. We also isolated microglia/macrophages from the mouse brains with ICH to analyze their morphology, phagocytosis ability, and polarization. Our study reveals that, 1) PSL-IL10 treatment resulted in significantly improved outcomes and accelerated hematoma resolution in the acute phase of ICH; 2) PSL-IL10 inhibited glial activation and down-regulated pro-inflammatory cytokine production; 3) PSL-IL10 induced Iba1+ cells with a stronger phagocytosis ability; 4) PSL-IL10 activated STAT3 and upregulated CD36 expression in microglia/macrophage. These findings collectively show that PSL-IL10 is a promising nanotherapeutic for effectively ameliorating ICH.
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•An efficient and targeted delivery method is needed for Interleukin-10-based intracerebral hemorrhage therapy.•Phosphatidylserine-liposomes offer a promising avenue for targeted delivery to microglia/macrophages in the brain.•Intranasally administered nanotherapeutic exhibits significantly enhanced therapeutic outcomes in a mouse model.•The study represents an innovative nanotherapeutic strategy for the effective treatment of intracerebral hemorrhage.
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