Organ Biodistribution Research Articles

Hyaluronate-Thiol Passivation Enhances Gold Nanoparticle Peritumoral Distribution When Administered Intratumorally in Lung Cancer.

Biofouling is the unwanted adsorption of cells, proteins, or intracellular and extracellular biomolecules that can spontaneously occur on the surface of metal nanocomplexes. It represents a major issue in bioinorganic chemistry because it leads to the creation of a protein corona, which can destabilize a colloidal solution and result in undesired macrophage-driven clearance, consequently causing failed delivery of a targeted drug cargo. Hyaluronic acid (HA) is a bioactive, natural mucopolysaccharide with excellent antifouling properties, arising from its hydrophilic and polyanionic characteristics in physiological environments which prevent opsonization. In this study, hyaluronate-thiol (HA-SH) (MW 10 kDa) was used to surface-passivate gold nanoparticles (GNPs) synthesized using a citrate reduction method. HA functionalized GNP complexes (HA-GNPs) were characterized using absorption spectroscopy, scanning electron microscopy, zeta potential, and dynamic light scattering. GNP cellular uptake and potential dose-dependent cytotoxic effects due to treatment were evaluated in vitro in HeLa cells using inductively coupled plasma—optical emission spectrometry (ICP-OES) and trypan blue and MTT assays. Further, we quantified the in vivo biodistribution of intratumorally injected HA functionalized GNPs in Lewis Lung carcinoma (LLC) solid tumors grown on the flank of C57BL/6 mice and compared localization and retention with nascent particles. Our results reveal that HA-GNPs show overall greater peritumoral distribution (** p < 0.005, 3 days post-intratumoral injection) than citrate-GNPs with reduced biodistribution in off-target organs. This property represents an advantageous step forward in localized delivery of metal nano-complexes to the infiltrative region of a tumor, which may improve the application of nanomedicine in the diagnosis and treatment of cancer.

Side-by-Side Comparison of uPAR-Targeting Optical Imaging Antibodies and Antibody Fragments for Fluorescence-Guided Surgery of Solid Tumors

PurposeRadical resection is paramount for curative oncological surgery. Fluorescence-guided surgery (FGS) aids in intraoperative identification of tumor-positive resection margins. This study aims to assess the feasibility of urokinase plasminogen activator receptor (uPAR) targeting antibody fragments for FGS in a direct comparison with their parent IgG in various relevant in vivo models.ProceduresHumanized anti-uPAR monoclonal antibody MNPR-101 (uIgG) was proteolytically digested into F(ab’)2 and Fab fragments named uFab2 and uFab. Surface plasmon resonance (SPR) and cell assays were used to determine in vitro binding before and after fluorescent labeling with IRDye800CW. Mice bearing subcutaneous HT-29 human colonic cancer cells were imaged serially for up to 120 h after fluorescent tracer administration. Imaging characteristics and ex vivo organ biodistribution were further compared in orthotopic pancreatic ductal adenocarcinoma (BxPc-3-luc2), head-and-neck squamous cell carcinoma (OSC-19-luc2-GFP), and peritoneal carcinomatosis (HT29-luc2) models using the clinical Artemis fluorescence imaging system.ResultsUnconjugated and conjugated uIgG, uFab2, and uFab specifically recognized uPAR in the nanomolar range as determined by SPR and cell assays. Subcutaneous tumors were clearly identifiable with tumor-to-background ratios (TBRs) > 2 after 72 h for uIgG-800F and 24 h for uFab2-800F and uFab-800F. For the latter two, mean fluorescence intensities (MFIs) dipped below predetermined threshold after 72 h and 36 h, respectively. Tumors were easily identified in the orthotopic models with uIgG-800F consistently having the highest MFIs and uFab2-800F and uFab-800F having similar values. In biodistribution studies, kidney and liver fluorescence approached tumor fluorescence after uIgG-800F administration and surpassed tumor fluorescence after uFab2-800F or uFab-800F administration, resulting in interference in the abdominal orthotopic mouse models.ConclusionsIn a side-by-side comparison, FGS with uPAR-targeting antibody fragments compared with the parent IgG resulted in earlier tumor visualization at the expense of peak fluorescence intensity.

Heptamethine Cyanine Dye MHI-148-Mediated Drug Delivery System to Enhance the Anticancer Efficiency of Paclitaxel.

IntroductionPaclitaxel (PTX) is a conventional chemotherapeutic drug that effectively treats various cancers. The cellular uptake and therapeutic potential of PTX are limited by its slow penetration and low solubility in water. The development of cancer chemotherapy methods is currently facing considerable challenges with respect to the delivery of the drugs, particularly in targeting the tumor site without exerting detrimental effects on the healthy surrounding cells. One possibility for improving the therapeutic potential is through the development of tumor-targeted delivery methods.MethodsWe successfully synthesized paclitaxel-MHI-148 conjugates (PTX-MHI) by coupling PTX with the tumor-targeting heptamethine cyanine dye MHI-148. Synthesis and purification were characterized using the absorbance spectrum and the results of time-of-flight mass spectrometry. Cellular uptake and cytotoxicity studies were conducted in vitro and in vivo.ResultsPTX-MHI accumulates in tumor cells but not in normal cells, as observed by in vitro near-infrared fluorescent (NIRF) imaging along with in vivo NIRF imaging and organ biodistribution studies. We observed that MHI-148-conjugated PTX shows greater efficiency in cancer cells than PTX alone, even in the absence of light treatment. PTX-MHI could also be used for specific drug delivery to intracellular compartments, such as the mitochondria and lysosomes of cancer cells, to improve the outcomes of tumor-targeting therapy.ConclusionThe results indicated that PTX-MHI-mediated cancer therapy exerts an excellent inhibitory effect on colon carcinoma (HT-29) cell growth with low toxicity in normal fibroblasts (NIH3T3).

Small Interfering RNA (siRNA) of Mini circle DNA Transfection (McD) is Encapsulated by Gold Nanoparticles from Folate’s Receptors of Gold Conjugation as Curative Therapy for Non-Small’s Cell of Lung Cancer

Background: Lung cancer is one of the non-communicable diseases that have an increasing number of events that each year with a mortality rate of 18.4% and an incidence of 11.6%, occupies the top position based on GLOBOCAN data in 2018. One of management in the NSCLC is currently in the form of surgery and adjuvant therapy such as chemotherapy, radiotherapy and target therapy. However, there were weaknesses and limitations in care for its patients therefore development of curative therapy for NSCLC’s patients were needed. The aim of this review is to learn and investigate about the potential of siRNA that is transfected into McD and folate receptors alpha-conjugated gold nanoparticle encapsulation as a therapeutic opportunity that could be developed as a treatment in management of NSCLC.Method: The writing method used in this review article was the study method of literature. The used data comes from 45 of relevant literature sources and was arranged systematically in accordance with the topic of the problem discussed, along with the inclusion and exclusion criteria.Result: This treatment could increase gene transfection, siRNA biodistribution in organs, reduced KRAS, Bcl-2, and VEGF expression. Moreover, siRNA had entered phase III clinical trials and FOLR1 antibodies were in phase II of clinical trials.Conclusion: Utilization of siRNA specifically was designed for three genes such for KRAS, VEGF and Bcl-2 which were three genes that played a role in the pathogenesis of NSCLC, could be the right modality choice for treatment of NSCLC.

Nanocurcumin-Loaded UCNPs for Cancer Theranostics: Physicochemical Properties, In Vitro Toxicity, and In Vivo Imaging Studies.

Formulation of promising anticancer herbal drug curcumin as a nanoscale-sized curcumin (nanocurcumin) improved its delivery to cells and organisms both in vitro and in vivo. We report on coupling nanocurcumin with upconversion nanoparticles (UCNPs) using Poly (lactic-co-glycolic Acid) (PLGA) to endow visualisation in the near-infrared transparency window. Nanocurcumin was prepared by solvent-antisolvent method. NaYF4:Yb,Er (UCNP1) and NaYF4:Yb,Tm (UCNP2) nanoparticles were synthesised by reverse microemulsion method and then functionalized it with PLGA to form UCNP-PLGA nanocarrier followed up by loading with the solvent-antisolvent process synthesized herbal nanocurcumin. The UCNP samples were extensively characterised with XRD, Raman, FTIR, DSC, TGA, UV-VIS-NIR spectrophotometer, Upconversion spectrofluorometer, HRSEM, EDAX and Zeta Potential analyses. UCNP1-PLGA-nanocurcumin exhibited emission at 520, 540, 660 nm and UCNP2-PLGA-nanocurmin showed emission at 480 and 800 nm spectral bands. UCNP-PLGA-nanocurcumin incubated with rat glioblastoma cells demonstrated moderate cytotoxicity, 60–80% cell viability at 0.12–0.02 mg/mL marginally suitable for therapeutic applications. The cytotoxicity of UCNPs evaluated in tumour spheroids models confirmed UCNP-PLGA-nanocurcumin therapeutic potential. As-synthesised curcumin-loaded nanocomplexes were administered in tumour-bearing laboratory animals (Lewis lung cancer model) and showed adequate contrast to enable in vivo and ex vivo study of UCNP-PLGA-nanocurcumin bio distribution in organs, with dominant distribution in the liver and lungs. Our studies demonstrate promise of nanocurcumin-loaded upconversion nanoparticles for theranostics applications.

68Ga-labeled ODAP-Urea-based PSMA agents in prostate cancer: first-in-human imaging of an optimized agent.

Prostate-specific membrane antigen (PSMA) is a promising target for prostate cancer imaging and therapy. The most commonly used scaffold incorporates a glutamate-urea (Glu-Urea) function. We recently developed oxalyldiaminopropionic acid-urea (ODAP-Urea) PSMA ligands in an attempt to improve upon the pharmacokinetic properties of existing agents. Here, we report the synthesis of an optimized 68Ga-labeled ODAP-Urea-based ligand, [68Ga]Ga-P137, and first-in-human results. Twelve ODAP-Urea-based ligands were synthesized and radiolabeled with 68Ga in high radiochemical yield and purity. Their PSMA inhibitory capacities were determined using the NAALADase assay. Radioligands were evaluated in mice-bearing 22Rv1 prostate tumors by microPET. Lead compound [68Ga]Ga-P137 was evaluated for stability, cell uptake, and biodistribution. PET imaging of [68Ga]Ga-P137 was performed in three patients head-to-head compared to [68Ga]Ga-PSMA-617. Ligands were synthesized in 11.1-44.4% yield and > 95% purity. They have high affinity to PSMA (Ki of 0.13 to 5.47nM). [68Ga]Ga-P137 was stable and hydrophilic. [68Ga]Ga-P137 showed higher uptake than [68Ga]Ga-PSMA-617 in tumor-bearing mice at 6.43 ± 0.98%IA/g vs 3.41 ± 1.31%IA/g at 60-min post-injection. In human studies, the normal organ biodistribution of [68Ga]Ga-P137 was grossly equivalent to that of [68Ga]Ga-PSMA-617 except for within the urinary tract, in which [68Ga]Ga-P137 demonstrated lower uptake. The optimized ODAP-Urea-based ligand [68Ga]Ga-P137 can image PSMA in xenograft models and humans, with lower bladder accumulation to the Glu-Urea-based agent, [68Ga]Ga-PSMA-617, in a preliminary, first-in-human study. ClinicalTrials.gov Identifier: NCT04560725, Registered 23 September 2020. https://clinicaltrials.gov/ct2/show/NCT04560725.

Comparison between Fluorescence Imaging and Elemental Analysis to Determine Biodistribution of Inorganic Nanoparticles with Strong Light Absorption.

Black porous silicon nanoparticles (BPSi NPs) are known as highly efficient infrared light absorbers that are well-suitable for photothermal therapy (PTT) and photoacoustic imaging (PAI). PTT and PAI require a sufficient number of effectively light-absorbing NPs to be accumulated in tumor after intravenous administration. Herein, biodistribution of PEGylated BPSi NPs with different sizes (i.e., 140, 200, and 300 nm in diameter) is investigated after intravenous administration in mice. BPSi NPs were conjugated with fluorescent dyes Cy5.5 and Cy7.5 to track them in vitro and in vivo, respectively. Optical imaging with an in vivo imaging system (IVIS) was found to be an inadequate technique to assess the biodistribution of the dye-labeled BPSi NPs in vivo because the intrinsic strong absorbance of the BPSi NPs interfered fluorescence detection. This challenge was resolved via the use of inductively coupled plasma optical emission spectrometry to analyze ex vivo the silicon content in different tissues and tumors. The results indicated that most of the polyethylene glycol-coated BPSi NPs were found to accumulate in the liver and spleen after intravenous injection. The smallest 140 nm particles accumulated the most in tumors at an amount of 9.5 ± 3.4% of the injected dose (concentration of 0.18 ± 0.08 mg/mL), the amount known to produce sufficient heat for cancer PTT. Furthermore, the findings from the present study also suggest that techniques other than optical imaging should be considered to study the organ biodistribution of NPs with strong light absorbance properties.

Differently PEGylated Polymer Nanoparticles for Pancreatic Cancer Delivery: Using a Novel Near-Infrared Emissive and Biodegradable Polymer as the Fluorescence Tracer.

In this study, a chemically synthetic polymer, benzo[1,2-b:4,5-b′]difuran(BDF)-based donor–acceptor copolymer PBDFDTBO, was individually coated by amphiphilic poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-PCL) and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-methoxy(polyethylene glycol) (DSPE-PEG or PEG-DSPE), to form stably fluorescent nanoparticles in the near-infrared (NIR) window. The physicochemical properties of the synthesized nanoparticles were characterized and compared, including their size, surface charge, and morphology. In addition, in vitro studies were also performed using two pancreatic cancer cell lines, assessing the cell viability of the PBDFDTBO-included PEGylated nanoparticles formulations. Moreover, in vivo studies were also conducted, using subcutaneous murine cancer models to investigate the polymeric nanoparticles’ circulation time, tumor accumulation, and preferred organ biodistribution. The overall results demonstrated that even with the same PEGylated surface, the hydrophobic composition anchored on the encapsulated PBDFDTBO core strongly affected the biodistribution and tumor accumulation of the nanoparticles, to a degree possibly determined by the hydrophobic interactions between the hydrophobic segment of amphiphilic polymers (DSPE or PCL moiety) and the enwrapped PBDFDTBO. Both PEGylated nanoparticles were compared to obtain an optimized coating strategy for a desired biological feature in pancreatic cancer delivery.

Clinical translational evaluation of Al18F-NOTA-FAPI for fibroblast activation protein-targeted tumour imaging.

In this study, a novel aluminium-[18F]fluoride (Al18F)-labelled 1,4,7‑triazacyclononane-N,N',N″-triacetic acid (NOTA)-conjugated fibroblast activation protein inhibitor (FAPI) probe, named Al18F-NOTA-FAPI, was developed for fibroblast activation protein (FAP)-targeted tumour imaging; it could deliver hundreds of millicuries of radioactivity using automated synthesis. The tumour detection efficacy of Al18F-NOTA-FAPI was further validated in both preclinical and clinical translational studies. The radiolabelling procedure of Al18F-NOTA-FAPI was optimized. Cell uptake and competitive binding assays were completed with the U87MG and A549 cell lines to evaluate the affinity and specificity of the Al18F-NOTA-FAPI probe. The biodistribution, pharmacokinetics, radiation dosimetry and tumour imaging efficacy of the Al18F-NOTA-FAPI probe were researched in healthy Kunming (KM) and/or U87MG model mice. After the approval of the ethical committee, the Al18F-NOTA-FAPI probe was translated into the clinic for PET/CT imaging of the first 10 cancer patients. The radiolabelling yield of Al18F-NOTA-FAPI was 33.8 ± 3.2% using manual synthesis (n = 10), with a radiochemical purity over 99% and the specific activity of 9.3-55.5MBq/nmol. The whole body effective dose of Al18F-NOTA-FAPI was estimated to be 1.24E - 02mSv/MBq, which was lower than several other FAPI probes (68Ga-FAPI-04, 68Ga-FAPI-46 and 68Ga-FAPI-74). In U87MG tumour-bearing mice, Al18F-NOTA-FAPI showed good tumour detection efficacy based on the results of micro PET/CT imaging and biodistribution studies. In an organ biodistribution study of patients, Al18F-NOTA-FAPI showed a lower SUVmean than 2-[18F]-fluoro-2-deoxy-D-glucose (2-[18F]FDG) in most organs, especially in the liver (1.1 ± 0.2 vs. 2.0 ± 0.9), brain (0.1 ± 0.0 vs. 5.9 ± 1.3), and bone marrow (0.9 ± 0.1 vs. 1.7 ± 0.4). Meanwhile, Al18F-NOTA-FAPI did not show extensive bone uptake, and was able to detect more lesions than 2-[18F]FDG in the PET/CT imaging of several patients. The Al18F-NOTA-FAPI probe was successfully fabricated and applied in fibroblast activation protein-targeted tumour PET/CT imaging, which showed excellent imaging quality and tumour detection efficacy in U87MG tumour-bearing mice as well as in cancer patients. Chinese Clinical Trial Registry ChiCTR2000038080. Registered 09 September 2020. http://www.chictr.org.cn/showproj.aspx?proj=61192.

Head-to-head intra-individual comparison of biodistribution and tumor uptake of 68Ga-FAPI and 18F-FDG PET/CT in cancer patients

PurposeFAPI ligands (fibroblast activation protein inhibitor), a novel class of radiotracers for PET/CT imaging, demonstrated in previous studies rapid and high tumor uptake. The purpose of this study is the head-to-head intra-individual comparison of 68Ga-FAPI versus standard-of-care 18F-FDG in PET/CT in organ biodistribution and tumor uptake in patients with various cancers.Material and MethodsThis international retrospective multicenter analysis included PET/CT data from 71 patients from 6 centers who underwent both 68Ga-FAPI and 18F-FDG PET/CT within a median time interval of 10 days (range 1–89 days). Volumes of interest (VOIs) were manually drawn in normal organs and tumor lesions to quantify tracer uptake by SUVmax and SUVmean. Furthermore, tumor-to-background ratios (TBR) were generated (SUVmax tumor/ SUVmax organ).ResultsA total of 71 patients were studied of, which 28 were female and 43 male (median age 60). In 41 of 71 patients, the primary tumor was present. Forty-three of 71 patients exhibited 162 metastatic lesions. 68Ga-FAPI uptake in primary tumors and metastases was comparable to 18F-FDG in most cases. The SUVmax was significantly lower for 68Ga-FAPI than 18F-FDG in background tissues such as the brain, oral mucosa, myocardium, blood pool, liver, pancreas, and colon. Thus, 68Ga-FAPI TBRs were significantly higher than 18F-FDG TBRs in some sites, including liver and bone metastases.ConclusionQuantitative tumor uptake is comparable between 68Ga-FAPI and 18F-FDG, but lower background uptake in most normal organs results in equal or higher TBRs for 68Ga-FAPI. Thus, 68Ga-FAPI PET/CT may yield improved diagnostic information in various cancers and especially in tumor locations with high physiological 18F-FDG uptake.

Synthesis and Characterization of a Positron Emission Tomography Imaging Probe Selectively Targeting the Second Bromodomain of Bromodomain Protein BRD4.

Two tandem bromodomains (BD1 and BD2) of bromodomain and extraterminal domain (BET) family proteins have shown distinct roles in mediating gene transcription and expression. Inhibitors that interact with a specific bromodomain may contribute to a specific therapeutic potential with fewer side effects. However, little is known about this disease-related target. Positron emission tomography (PET) imaging could allow us to achieve in-depth knowledge of the BD2 bromodomain. Herein we describe the radiosynthesis and evaluation of [11C]1 as a BRD4 BD2 bromodomain PET imaging radioligand. Our preliminary PET imaging results in rodents demonstrated that [11C]1 had suitable biodistribution in peripheral organs and tissues. Further blocking studies indicated that [11C]1 had good binding specificity toward the BD2 bromodomain. This study may pave the way for the development of a PET radioligand specifically targeting BD1/2 bromodomains as well as for the biological mechanism investigation of BD1/2 bromodomains.

Tumor Sink Effect in 68Ga-PSMA-11 PET: Myth or Reality?

We aimed to systematically determine the impact of tumor burden on 68Ga-prostate-specific membrane antigen-11 (68Ga-PSMA) PET biodistribution by the use of quantitative measurements. Methods: This international multicenter, retrospective analysis included 406 men with prostate cancer who underwent 68Ga-PSMA PET/CT. Of these, 356 had positive findings and were stratified by quintiles into a very low (quintile 1, ≤25 cm3), low (quintile 2, 25-189 cm3), moderate (quintile 3, 189-532 cm3), high (quintile 4, 532-1,355 cm3), or very high (quintile 5, ≥1,355 cm3) total PSMA-positive tumor volume (PSMA-VOL). PSMA-VOL was obtained by semiautomatic segmentation of total tumor lesions using qPSMA software. Fifty prostate cancer patients with no PSMA-positive lesions (negative scan) served as a control group. Normal organs, which included salivary glands, liver, spleen, and kidneys, were semiautomatically segmented using 68Ga-PSMA PET images, and SUVmean was obtained. Correlations between the SUVmean of normal organs and PSMA-VOL as continuous and categoric variables by quintiles were evaluated. Results: The median PSMA-VOL was 302 cm3 (interquartile range [IQR], 47-1,076 cm3). The median SUVmean of salivary glands, kidneys, liver, and spleen was 10.0 (IQR, 7.7-11.8), 26.0 (IQR, 20.0-33.4), 3.7 (IQR, 3.0-4.7), and 5.3 (IQR, 4.0-7.2), respectively. PSMA-VOL showed a moderate negative correlation with the SUVmean of the salivary glands (r = -0.44, P < 0.001), kidneys (r = -0.34, P < 0.001), and liver (r = -0.30, P < 0.001) and a weak negative correlation with the spleen SUVmean (r = -0.16, P = 0.002). Patients with a very high PSMA-VOL (quintile 5, ≥1,355 cm3) had a significantly lower PSMA uptake in the salivary glands, kidneys, liver, and spleen than did the control group, with an average difference of -38.1%, -40.0%, -43.2%, and -34.9%, respectively (P < 0.001). Conclusion: Tumor sequestration affects 68Ga-PSMA biodistribution in normal organs. Patients with a very high tumor load showed a significantly lower uptake of 68Ga-PSMA in normal organs, confirming a tumor sink effect. As similar effects might occur with PSMA-targeted radioligand therapy, these patients might benefit from increased therapeutic activity without exceeding the radiation dose limit for organs at risk.

Dosimetry and optimal scan time of [18F]SiTATE-PET/CT in patients with neuroendocrine tumours

PurposeRadiolabelled somatostatin analogues targeting somatostatin receptors (SSR) are well established for combined positron emission tomography/computer tomography (PET/CT) imaging of neuroendocrine tumours (NET). [18F]SiTATE has recently been introduced showing high image quality, promising clinical performance and improved logistics compared to the clinical reference standard 68Ga-DOTA-TOC. Here we present the first dosimetry and optimal scan time analysis.MethodsEight NET patients received a [18F]SiTATE-PET/CT (250 ± 66 MBq) with repeated emission scans (10, 30, 60, 120, 180 min after injection). Biodistribution in normal organs and SSR-positive tumour uptake were assessed. Dosimetry estimates for risk organs were determined using a combined linear-monoexponential model, and by applying 18F S-values and reference target masses for the ICRP89 adult male or female (OLINDA 2.0). Tumour-to-background ratios were compared quantitatively and visually between different scan times.ResultsAfter 1 h, normal organs showed similar tracer uptake with only negligible changes until 3 h post-injection. In contrast, tracer uptake by tumours increased progressively for almost all types of metastases, thus increasing tumour-to-background ratios over time. Dosimetry resulted in a total effective dose of 0.015 ± 0.004 mSv/MBq. Visual evaluation revealed no clinically relevant discrepancies between later scan times, but image quality was rated highest in 60 and 120 min images.Conclusion[18F]SiTATE-PET/CT in NET shows overall high tumour-to-background ratios from 60 to 180 min after injection and an effective dose comparable to 68Ga-labelled alternatives. For clinical use of [18F]SiTATE, the best compromise between image quality and tumour-to-background contrast is reached at 120 min, followed by 60 min after injection.

Efficient in vitro and in vivo docetaxel delivery mediated by pH-sensitive LPHNPs for effective breast cancer therapy

The present study was designed to develop pH-sensitive lipid polymer hybrid nanoparticles (pHS-LPHNPs) for specific cytosolic-delivery of docetaxel (DTX). The pHS-LPHNPs-DTX formulation was prepared by self-assembled nano-precipitation technique and characterized for zeta potential, particle size, entrapment efficiency, polydispersity index (PDI), and in vitro drug release. In vitro cytotoxicity of pHS-LPHNPs-DTX was assessed on breast cancer cells (MDA-MB-231 and MCF-7) and compared with DTX-loaded conventional LPHNPs and bare DTX. In vitro cellular uptake in MDA-MB-231 cell lines showed better uptake of pHS-LPHNPs. Further, a significant reduction in the IC50 of pHS-LPHNPs-DTX against both breast cancer cells was observed. Flow cytometry results showed greater apoptosis in case of pHS-LPHNPs-DTX treated MDA-MB-231 cells. Breast cancer was experimentally induced in BALB/c female mice, and the in vivo efficacy of the developed pHS-LPHNPs formulation was assessed with respect to the pharmacokinetics, biodistribution in the vital organs (liver, kidney, heart, lungs, and spleen), percentage tumor burden, and survival of breast cancer-bearing animals. In vivo studies showed improved pharmacokinetic and target-specificity with minimum DTX circulation in the deep-seated organs in the case of pHS-LPHNPs-DTX compared to the LPHNPs-DTX and free DTX. Mice treated with pHS-LPHNPs-DTX exhibited a significantly lesser tumor burden than other treatment groups. Also, reduced distribution of DTX in the serum was evident for pHS-LPHNPs-DTX treated mice compared to the LPHNPs-DTX and free DTX. In essence, pHS-LPHNPs mediated delivery of DTX presents a viable platform for developing therapeutic-interventions against breast-cancer.

Design, development and in-vitro/in-vivo evaluation of intranasally delivered Rivastigmine and N-Acetyl Cysteine loaded bifunctional niosomes for applications in combinative treatment of Alzheimer’s disease

The present investigation explores the potential of novel dual drug-loaded niosomes for nasal delivery of Rivastigmine (RIV) and N-Acetyl Cysteine (NAC) to the brain. The dual niosomes showed a particle size of 162.4 nm and % entrapment efficiencies of 97.7% for RIV and 85.9% for NAC. The niosomes were statistically validated using Box-Behnken experimental design (BBD) with good significance. Ultrastructural and chemical characterization of the niosomes using various analytical techniques like Fourier Transform Infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC), Transmission electron microscopy (TEM) showcased drug-excipient compatibility and robust stability of 6 months in a liquid state at 4–8 °C. The dual drug-loaded niosomes showed a sustained drug release pattern up to 2 days. Acetylcholinesterase (AChE) and DPPH (1, 1-diphenyl-2- picrylhydrazyl) enzyme inhibition assays showed a better combinative effect than the free drug solutions. A 2-day nasal permeation proved the effectiveness and biocompatibility of the niosomes. In-vivo pharmacokinetic and organ biodistribution studies revealed a better drug profile and greater distribution of the niosomes in the brain compared to other organs, thereby indicating a direct nose-to-brain delivery of the niosomes.

Small Molecule, Multimodal, [18F]-PET and Fluorescence Imaging Agent Targeting Prostate-Specific Membrane Antigen: First-in-Human Study

A first-in-human study of [18F]-BF3-Cy3-ACUPA, a small-molecule imaging agent that can be unimolecularly both positron emitting and fluorescent, is conducted to determine its safety, biodistribution, radiation dosimetry, feasibility in tumor detection by preoperative positron emission tomography (PET), as well as its intraoperative fluorescence imaging utility in patients with prostate-specific membrane antigen positive (PSMA+) tumors. Ten patients aged 66 ± 7 years received a 6.5 ± 3.2 mCi intravenous injection of [18F]-BF3-Cy3-ACUPA and underwent PET/computed tomography (CT) imaging. Radiation dosimetry of [18F]-BF3-Cy3-ACUPA, normal organ biodistribution, and tumor uptakes were examined. Two patients were prescheduled for radical prostatectomy (RP) with extended pelvic lymphadenectomy approximately 24 hours following [18F]-BF3-Cy3-ACUPA injection and imaging. Without reinjection, intraoperative fluorescence imaging was performed on freshly excised tissue during RP. Frozen sections of excised tissue during RP were submitted for confirmatory histopathology and multiphoton fluorescence and brightfield microscopy. Absorbed doses by organs including the kidneys and salivary glands were similar to 68Ga-PSMA-11 imaging. [18F]-BF3-Cy3-ACUPA physiologic radiotracer accumulation and urinary/biliary excretion closely resembled the distribution of other published PSMA tracers including [18F]-JK-PSMA-7, [18F]-PSMA-1007, [18F]-DCFPyL, and [18F]-DCFBC. 19F-BF3-Cy3-ACUPA was retained in PSMA+ cancer tissues in patients for at least 24 hours, allowing for intraoperative fluorescence assessment of the prostate and of the embedded prostate cancer without contrast reinjection. After 24 hours, the imaging agent mostly decayed or cleared from the blood pool. Preoperative PET and fluorescence imaging findings were confirmed with final histopathology and multiphoton microscopy. Our first-in-human results demonstrate that [18F]-BF3-Cy3-ACUPA is safe and feasible in humans. Larger trials with this PET tracer are expected to further define its capabilities and its clinical role in the management of PSMA+ tumors, especially in prostate cancer.

Remote effects and biodistribution of pulmonary instilled silver nanoparticles in mice

Silver nanoparticles (AgNPs) are the most commonly used nanoparticles (NPs) owing to their anti-microbial properties, and the pulmonary system provides a major portal of entry for these NPs used in aerosolized products. AgNPs have the potential to cause pulmonary toxicity, cross the alveolar-capillary barrier, and distribute to remote organs following pulmonary exposure. The mechanism underlying the effects of AgNPs, secondary to lung exposure, on the major organs including liver, spleen, kidney and brain, however, is still not completely understood. The aim of this study was to analyze the organ toxicity and distribution of pulmonary exposure to single dose of 5 mg/kg AgNPs (10 nm) with varying coatings (polyvinylpyrrolidone and citrate), at different time points (1 and 7 days), in Balb/C mice. Silver ions (Ag+) were used as ionic control. Histological evidence of inflammation was observed in lungs for both types of AgNPs. Markers of inflammation including tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) were significantly increased in lung, brain and liver in AgNPs exposed animals. Ag+ ions caused significant increase of TNF-α and IL-6 in the spleen and kidney. Significant increase of reduced glutathione, nitric oxide, and 8-isoprostane was observed in most of the organs investigated. Furthermore, AgNPs induced DNA damage and apoptosis in the lung, liver and brain. The biodistribution showed that, AgNPs were distributed mainly in the spleen, liver, lung and little in kidney and brain. Comparatively, reduced amount of Ag was detected in most organs 7 days after exposure, except for AgAc in the kidney and brain. In conclusion, pulmonary exposure to AgNPs caused oxidative stress markers, inflammation, DNA damage and biodistribution in remote organs. These findings provide a novel mechanistic insight into the pathophysiological effects and tissue distribution of lung exposure to AgNPs.

Synthesis, preclinical evaluation, and a pilot clinical imaging study of [18F]AlF-NOTA-JR11 for neuroendocrine neoplasms compared with [68Ga]Ga-DOTA-TATE.

A [18F]AlF-labeled somatostatin receptor (SSTR) antagonist was developed for imaging of neuroendocrine neoplasms (NENs), evaluated and compared with [68Ga]Ga-DOTA-TATE. [18F]AlF-NOTA-JR11 was synthesized manually and qualified with high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). The cellular uptake, internalization, and saturation binding were performed with HEK293-SSTR2 cells. Biodistribution and micro-PET imaging were carried out with HEK293-SSTR2 tumor-bearing mice. [18F]AlF-NOTA-JR11 PET/MR imaging and [68Ga]Ga-DOTA-TATE PET/CT were performed with ten patients of NEN at 50~60min post-injection (p.i.). Normal organ biodistribution and tumor detectability were evaluated. [18F]AlF-NOTA-JR11(24~36GBq/μmol) was prepared within 30min and 51.35 ± 3.30% (n > 10)of radiochemical yield. The radiochemical purity was 98.74 ± 1.24% (n > 10). Two stereoisomers were found and confirmed by LC-MS. The cellular uptake of [18F]AlF-NOTA-JR11 and [68Ga]Ga-DOTA-TATE were 4.50 ± 0.31 and 4.50 ± 0.13 %AD/105 cells at 30min, and the internalization at 37°C of [18F]AlF-NOTA-JR11 (5.47 ± 0.32% at 60min) was significantly lower than [68Ga]Ga-DOTA-TATE (66.89 ± 1.62% at 60min). The affinity of [18F]AlF-NOTA-JR11 (Kd = 11.59 ± 1.31nM) was slightly lower than [68Ga]Ga-DOTA-TATE (Kd = 7.36 ± 1.02nM); [18F]AlF-NOTA-JR11 showed high uptake in tumor (9.02 ± 0.92 %ID/g at 60min p.i.) which can be blocked by 50μg of NOTA-JR11 (3.40 ± 1.64 %ID/g at 60min p.i.); the result was coincident with micro-PET imaging. Imaging study of NEN patients showed that more lesions were found only by [18F]AlF-NOTA-JR11 (n = 67 vs. 1 only by [68Ga]Ga-DOTA-TATE), and the uptakes of [18F]AlF-NOTA-JR11 in majority normal organs were significantly lower than [68Ga]Ga-DOTA-TATE. The target to nontarget of maximum of standard uptake value (SUVmax) of [18F]AlF-NOTA-JR11 in liver lesions were significantly higher than those of [68Ga]Ga-DOTA-TATE. Qualitied [18F]AlF-NOTA-JR11 is prepared conveniently with reasonable yield, and it can bind SSTR2 specifically with high affinity. Excellent imaging capability of [18F]AlF-NOTA-JR11 for NENs is superior to [68Ga]Ga-DOTA-TATE, especially in digestive system. It has a great potential for imaging of NENs.

A Prospective, Randomized, Double-Blind Study to Evaluate the Safety, Biodistribution, and Dosimetry of 68Ga-NODAGA-LM3 and 68Ga-DOTA-LM3 in Patients with Well-Differentiated Neuroendocrine Tumors.

68Ga-NODAGA-LM3 (where LM3 is p-Cl-Phe-cyclo(d-Cys-Tyr-d-4-amino-Phe(carbamoyl)-Lys-Thr-Cys)d-Tyr-NH2) and 68Ga-DOTA-LM3 are somatostatin receptor subtype 2 (SSTR2)-specific antagonists used for PET/CT imaging. The purpose of this study was to evaluate the safety, biodistribution, and dosimetry of 68Ga-NODAGA-LM3 and 68Ga-DOTA-LM3 in patients with well-differentiated neuroendocrine tumors. Methods: Patients were equally randomized into 2 arms, with arm A receiving 68Ga-NODAGA-LM3 and arm B receiving 68Ga-DOTA-LM3. Serial PET scans were acquired at 5, 15, 30, 45, 60, and 120 min after 68Ga-NODAGA-LM3 (200 MBq ± 11 MBq/40 μg of total peptide mass) or 68Ga-DOTA-LM3 (172 MBq ± 21 MBq/40 μg of total peptide mass) injection. The biodistribution in normal organs, tumor uptake, and safety were assessed. Radiation dosimetry was calculated using OLINDA/EXM (version 1.0). Results: Sixteen patients, 8 in each arm, were recruited in the study. Both tracers were well tolerated in most patients. Two patients in arm B had nausea (grade 2), and one of them had vomiting (grade 1). The PET images of the other 14 patients were further analyzed. Significantly lower organ uptake was observed in the pituitary, parotids, liver, spleen, pancreas, adrenal, stomach, small intestine, and kidneys with 68Ga-DOTA-LM3 than with 68Ga-NODAGA-LM3. In total, 38 lesions were analyzed, including 18 with 68Ga-NODAGA-LM3 and 20 with 68Ga-DOTA-LM3. Both tracers showed good tumor uptake and retention. With 68Ga-NODAGA-LM3, the tracer accumulation in tumor lesions increased by 138%, from an average SUVmax of 31.3 ± 19.7 at 5 min to 74.6 ± 56.3 at 2 h. With 68Ga-DOTA-LM3, the tumor uptake rapidly reached a high level at 5 min after injection, with an average SUVmax of 36.6 ± 23.6, and continued to increase to 45.3 ± 29.3 until 30 min after injection. The urinary bladder wall was the organ receiving the highest absorbed dose in both arms. The mean effective dose was 0.026 ± 0.003 mSv/MBq for 68Ga-NODAGA-LM3 and 0.025 ± 0.002 mSv/MBq for 68Ga-DOTA-LM3. Conclusion: Both 68Ga-NODAGA-LM3 and 68Ga-DOTA-LM3 show favorable biodistribution, high tumor uptake, and good tumor retention, resulting in high image contrast. The dosimetric data are comparable to those for other 68Ga-labeled SSTR2 antagonists. Further studies are required to look into the potential antagonistic effects of 68Ga-NODAGA-LM3 and 68Ga-DOTA-LM3.

Systemic AAV6-synapsin-GFP administration results in lower liver biodistribution, compared to AAV1&2 and AAV9, with neuronal expression following ultrasound-mediated brain delivery

Non-surgical gene delivery to the brain can be achieved following intravenous injection of viral vectors coupled with transcranial MRI-guided focused ultrasound (MRIgFUS) to temporarily and locally permeabilize the blood–brain barrier. Vector and promoter selection can provide neuronal expression in the brain, while limiting biodistribution and expression in peripheral organs. To date, the biodistribution of adeno-associated viruses (AAVs) within peripheral organs had not been quantified following intravenous injection and MRIgFUS delivery to the brain. We evaluated the quantity of viral DNA from the serotypes AAV9, AAV6, and a mosaic AAV1&2, expressing green fluorescent protein (GFP) under the neuron-specific synapsin promoter (syn). AAVs were administered intravenously during MRIgFUS targeting to the striatum and hippocampus in mice. The syn promoter led to undetectable levels of GFP expression in peripheral organs. In the liver, the biodistribution of AAV9 and AAV1&2 was 12.9- and 4.4-fold higher, respectively, compared to AAV6. The percentage of GFP-positive neurons in the FUS-targeted areas of the brain was comparable for AAV6-syn-GFP and AAV1&2-syn-GFP. In summary, MRIgFUS-mediated gene delivery with AAV6-syn-GFP had lower off-target biodistribution in the liver compared to AAV9 and AAV1&2, while providing neuronal GFP expression in the striatum and hippocampus.