Direct and Indirect Chimeric Antigen Receptor T-Cell Imaging with PET/MRI in a Tumor Xenograft Model.

Background Chimeric antigen receptor (CAR) T cells are a promising cancer therapy; however, reliable and repeatable methods for tracking and monitoring CAR T cells in vivo remain underexplored. Purpose To investigate direct and indirect imaging strategies for tracking the biodistribution of CAR T cells and monitoring their therapeutic effect in target tumors. Materials and Methods CAR T cells co-expressing a tumor-targeting gene (anti-CD19 CAR) and a human somatostatin receptor subtype 2 (hSSTr2) reporter gene were generated from human peripheral blood mononuclear cells. After direct labeling with zirconium 89 (89Zr)-p-isothiocyanatobenzyl-desferrioxamine (DFO), CAR T cells were intravenously injected into immunodeficient mice with a CD19-positive and CD19-negative human tumor xenograft on the left and right flank, respectively. PET/MRI was used for direct in vivo imaging of 89Zr-DFO-labeled CAR T cells on days 0, 1, 3, and 7 and for indirect cell imaging with the radiolabeled somatostatin receptor-targeted ligand gallium 68 (68Ga)-DOTA-Tyr3-octreotide (DOTATOC) on days 6, 9, and 13. On day 13, mice were euthanized, and tissues and tumors were excised. Results The 89Zr-DFO-labeled CAR T cells were observed on PET/MRI scans in the liver and lungs of mice (n = 4) at all time points assessed. However, they were not visualized in CD19-positive or CD19-negative tumors, even on day 7. Serial 68Ga-DOTATOC PET/MRI showed CAR T cell accumulation in CD19-positive tumors but not in CD19-negative tumors from days 6 to 13. Notably, 68Ga-DOTATOC accumulation in CD19-positive tumors was highest on day 9 (mean percentage injected dose [%ID], 3.7% ± 1.0 [SD]) and decreased on day 13 (mean %ID, 2.6% ± 0.7) in parallel with a decrease in tumor volume (day 9: mean, 195 mm3 ± 27; day 13: mean, 127 mm3 ± 43) in the group with tumor growth inhibition. Enhanced immunohistochemistry staining of cluster of differentiation 3 (CD3) and hSSTr2 was also observed in excised CD19-positive tumor tissues. Conclusion Direct and indirect cell imaging with PET/MRI enabled in vivo tracking and monitoring of CAR T cells in an animal model. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Bulte in this issue.

Application of TSPO-Specific Positron Emission Tomography Radiotracer as an Early Indicator of Acute Liver Failure Induced by Propacetamol, a Prodrug of Paracetamol.

Acetaminophen overdose is a leading cause of acute liver failure (ALF), and effective treatment depends on early prediction of disease progression. ALF diagnosis currently requires blood collection 24-72 h after APAP ingestion, necessitating repeated tests and hospitalization. Here, we assessed earlier ALF diagnosis using positron emission tomography (PET) imaging of translocator proteins (TSPOs), which are involved in molecular transport, oxidative stress, apoptosis, and energy metabolism, with the radiotracer [18F]GE180. We intraperitoneally administered propacetamol hydrochloride to male C57BL/6 mice to induce ALF. We performed in vivo PET/CT imaging 3 h later using the TSPO-specific radiotracer [18F]GE180 and quantitatively analyzed the PET images by determining the averaged standardized uptake value (SUVav) in the liver parenchyma. We assessed liver TSPO expression levels via real-time polymerase chain reaction, Western blotting, and immunohistochemistry. [18F]GE180 PET imaging 3 h after propacetamol administration (1500 mg/kg) significantly increased liver SUVav compared to controls (p = 0.001). Analyses showed a 10-fold and 4-fold increase in TSPO gene and protein expression, respectively, in the liver, 3 h after propacetamol induction compared to controls. [18F]GE180 PET visualized and quantified propacetamol-induced ALF through TSPO overexpression. These findings highlight TSPO PET's potential as a non-invasive imaging biomarker for early-stage ALF.

A novel chalcone derivative exerts anticancer effects by promoting apoptotic cell death of human pancreatic cancer cells.

Aggressive pancreatic cancer is typically treated using chemotherapeutics to reduce the tumor pre-operatively and prevent metastasis post-operatively, as well as surgical approaches. In the present study, we synthesized a hydroxyl group-introduced chalcone derivative (1, IC50 = 32.1 µM) and investigated its potential as an anticancer drug candidate by evaluating its apoptosis-promoting effects on BXPC-3 cancer cells. The viability of BXPC-3 cells treated with 1 was measured using the water-soluble tetrazolium 1 reagent. BXPC-3 cells induced by 1 were stained with diverse probes or antibodies, such as ethidium homodimer-1, Hoechst, anti-Ki67, and MitoTracker. Protein expression was measured using an immunoblotting assay, and mRNA expression was determined using real-time polymerase chain reaction. Apoptotic molecular features, such as lipid accumulation and protein degradation, were monitored directly using stimulated Raman scattering microspectroscopy. Through incubation time- and concentration-dependent studies of 1, we found that it significantly reduced the proliferation and increased the number of apoptotic BXPC-3 cells. Compound 1 induced mitochondrial dysfunction, phosphorylation of p38, and caspase 3 cleavage. These results indicate that 1 is a potential therapeutic agent for pancreatic cancer, providing valuable insights into the development of new anticancer drug candidates.

Smart Vitamin Micelles as Cancer Nanomedicines for Enhanced Intracellular Delivery of Doxorubicin.

Chemotherapy is one of the most effective treatments for cancer. However, intracellular delivery of many anticancer drugs is hindered by their hydrophobicity and low molecular weight. Here, we describe highly biocompatible and biodegradable amphiphilic vitamin conjugates comprising hydrophobic vitamin E and hydrophilic vitamin B labeled with dual pH and glutathione-responsive degradable linkages. Vitamin-based micelles (vitamicelles), formed by self-assembly in aqueous solutions, were optimized based on their stability after encapsulation of doxorubicin (DOX). The resulting vitamicelles have great potential as vehicles for anticancer drugs because they show excellent biocompatibility (>94% after 48 h of incubation) and rapid biodegradability (>90% after 2.5 h). Compared with free DOX, DOX-loaded vitamicelles showed a markedly enhanced anticancer effect as they released the drug rapidly and inhibited drug efflux out of cells efficiently. By exploiting these advantages, this study not only provides a promising strategy for circumventing existing challenges regarding the delivery of anticancer drugs but also extends the utility of current DOX-induced chemotherapy.

Gold nanoshell-mediated photothermal therapy for acne vulgaris.

Acne vulgaris, a common and chronic disorder of the pilosebaceous unit, affects up to 85% of adolescent and young adults. Although the current treatment options are effective, they are associated with unwanted side effects, chronicity, relapses, and recurrences. Recently, the Food and Drug Administration approved topical application of gold microparticles for selective photothermolysis to treat acne vulgaris. Here, we report two cases showing the efficacy of gold nanoshell-mediated photothermal therapy for recurrent acne that were refractory to previous treatments. In both cases, three sessions of photothermal therapy prevented the development of new lesions during a follow-up period of 3-4 months without causing any adverse effects. The two cases reported here demonstrate the possibility of gold nanoshell-mediated photothermal therapy as a safe and effective treatment for recurrent acne vulgaris in Asian patients.

Successful Treatment of Pigmentary Disorders in Asians With a Novel 730-nm Picosecond Laser.

BACKGROUND AND OBJECTIVE: Until recently, quality-switched nanosecond lasers have been the workhorse lasers in treating pigmented lesions. However, the recently commercialized picosecond lasers have provided physicians with a novel method to manage pigmented lesions. Most recently, the first picosecond laser with a 730-nm wavelength was developed to specifically target melanin and melanocytes. STUDY DESIGN/MATERIALS AND METHODS: We report on two Asian patients with freckles, lentigines, and melasma who were successfully treated with a novel 730-nm Ti:Sapphire picosecond laser (Picoway®; Syneron Candela, Corp). The clinical outcome was measured by the global percent of clearance, which was evaluated by blinded observers by comparing the post-treatment photographs with the baseline photographs. RESULTS: In both patients, a significant pigmentary reduction was achieved with only one treatment session. In both patients, the treatments were well tolerated with minimal discomfort even without topical anesthesia. No post-inflammatory hyperpigmentation or repigmentation was observed until the 6-week follow-up. The pigmentary conditions treated included freckles, lentigines, and melasma. Both subjects showed clinical improvement, with the best results observed for the treatment of freckles such that 95% of the lesions achieved excellent response (75-94% lightening). CONCLUSION: The results of this case report indicate that a novel 730-nm Ti:Sapphire picosecond laser may be effective and safe in treating pigmentary disorders in darker-skinned patients. Therefore, further well-designed, prospective clinical trials are warranted to establish the potential of 730-nm picosecond lasers and determine the optimal treatment parameters in comparison to existing laser and light modalities. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Enhanced Power Conversion Efficiency of Dye-Sensitized Solar Cells by Band Edge Shift of TiO2 Photoanode.

By simple soaking titanium dioxide (TiO2) films in an aqueous Na2S solution, we could prepare surface-modified photoanodes for application to dye-sensitized solar cells (DSSCs). An improvement in both the open-circuit voltage (Voc) and the fill factor (FF) was observed in the DSSC with the 5 min-soaked photoanode, compared with those of the control cell without any modification. The UV-visible absorbance spectra, UPS valence band spectra, and dark current measurements revealed that the Na2S modification led to the formation of anions on the TiO2 surface, and thereby shifted the conduction band edge of TiO2 in the negative (upward) direction, inducing an increase of 29 mV in the Voc. It was also found that the increased FF value in the surface-treated device was attributed to an elevation in the shunt resistance.

Heat shock protein 90 inhibitor AUY922 attenuates platelet-derived growth factor-BB-induced migration and proliferation of vascular smooth muscle cells.

Luminespib (AUY922), a heat shock proteins 90 inhibitor, has anti-neoplastic and antitumor effects. However, it is not clear whether AUY922 affects events in vascular diseases. We investigated the effects of AUY922 on the platelet-derived growth factor (PDGF)-BB-stimulated proliferation and migration of vascular smooth muscle cells (VSMC). VSMC viability was detected using the XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) reagent. To detect the attenuating effects of AUY922 on PDGF-BB-induced VSMCs migration in vitro, we performed the Boyden chamber and scratch wound healing assays. To identify AUY922-mediated changes in the signaling pathway, the phosphorylation of protein kinase B (Akt) and extracellular signal-regulated kinase (ERK) 1/2 was analyzed by immunoblotting. The inhibitory effects of AUY922 on migration and proliferation ex vivo were tested using an aortic ring assay. AUY922 was not cytotoxic at concentrations up to 5 nM. PDGF-BB-induced VSMC proliferation, migration, and sprout outgrowth were significantly decreased by AUY922 in a dose-dependent manner. AUY922 significantly reduced the PDGF-BB-stimulated phosphorylation of Akt and ERK1/2. Furthermore, PD98059 (a selective ERK1/2 inhibitor) and LY294002 (a selective Akt inhibitor) decreased VSMC migration and proliferation by inhibiting phosphorylation of Akt and ERK1/2. Greater attenuation of PDGF-BB-induced cell viability and migration was observed upon treatment with PD98059 or LY294002 in combination with AUY922. AUY922 showed anti-proliferation and anti-migration effects towards PDGF-BBinduced VSMCs by regulating the phosphorylation of ERK1/2 and Akt. Thus, AUY922 is a candidate for the treatment of atherosclerosis and restenosis.

Diagnostic accuracy and safety of 16α-[18F]fluoro-17ß-oestradiol PET-CT for the assessment of oestrogen receptor status in recurrent or metastatic lesions in patients with breast cancer: a prospective cohort study.

BACKGROUND: A biopsy of first recurrence or metastatic disease is recommended to re-evaluate oestrogen receptor status in patients with breast cancer and to select appropriate treatment. However, retesting for oestrogen receptor status with rebiopsy is not always feasible, depending on lesion location and the risk associated with biopsy, and in these cases clinicians continue to treat patients according to the oestrogen receptor status of the primary tumour. Consequently suboptimal therapy might be offered to these patients. We assessed the diagnostic accuracy and safety of 16α-[18F]fluoro-17ß-oestradiol (18F-FES) PET-CT to assess oestrogen receptor status in patients with recurrent or metastatic breast cancer. METHODS: We did a prospective cohort study at the Asan Medical Center, Seoul, South Korea. Eligible patients had breast cancer, with first recurrence or metastatic disease at presentation, were 19 years or older, and had an Eastern Cooperative Oncology Group performance status of 0-2. The primary objective was to show the agreement between qualitative 18F-FES PET-CT interpretation and the results of oestrogen receptor expression by immunohistochemical assay, a non-reference standard test. Whole-body 18F-FES PET-CT imaging was done after intravenous injection of 111-222 MBq of 18F-FES, with dosing primarily determined by radiation dosimetry analysis. 18F-FES uptake above background intensity was interpreted as positive. Efficacy was assessed in all patients with histologically confirmed recurrent or metastatic breast cancer who received 18F-FES and had PET-CT images available (intention-to-diagnose analysis), and safety was assessed in all patients who received 18F-FES. This study is registered with ClinicalTrials.gov, number NCT01986569. FINDINGS: Between Nov 27, 2013, and Nov 10, 2016, 93 patients were enrolled. Of the 85 patients included in the efficacy analysis, 47 (55%) were oestrogen receptor-positive and 38 (45%) were oestrogen receptor-negative. Positive status percent agreement between the 18F-FES PET-CT results and oestrogen receptor status by immunohistochemical assay was 76·6% (95% CI 62·0-87·7) and the negative status percent agreement was 100·0% (90·8-100·0). Patients who were oestrogen receptor-positive and had a positive 18F-FES PET-CT result had a significantly higher progesterone receptor expression than those who were oestrogen receptor-positive and had a negative 18F-FES PET-CT result (23 [68%] of 34 patients vs 0 of 11 patients; p<0·0001). The most common adverse event was procedural pain in nine (10%) of 90 patients injected with 18F-FES. No adverse events were related to the study drug except injection site pain in one (1%) patient. No serious adverse events were recorded. INTERPRETATION: The high negative percent agreement between 18F-FES PET-CT and oestrogen receptor status by immunohistochemical assay in this cohort suggests that positive 18F-FES uptake by recurrent or metastatic oestrogen receptor-positive breast cancer lesions could be an alternative to oestrogen receptor assays in this setting. Staging assessment should include 18F-FES PET-CT when retesting oestrogen receptor status is not feasible. FUNDING: Asan Institute for Life Sciences, Ministry of Health and Welfare, South Korea.

Differences in gray and white matter 18F-THK5351 uptake between behavioral-variant frontotemporal dementia and other dementias.

PURPOSE: We investigated the regional distribution of 18F-THK5351 uptake in gray (GM) and white matter (WM) in patients with behavioral-variant frontotemporal dementia (bvFTD) and compared it with that in patients with Alzheimer's disease (AD) or semantic dementia (SD). METHODS: 18F-THK-5351 positron emission tomography (PET), 18F-florbetaben PET, magnetic resonance imaging, and neuropsychological testing were performed in 103 subjects including 30, 24, 9, and 8 patients with mild cognitive impairment, AD, bvFTD, and SD, respectively, and 32 normal subjects. Standardized uptake value ratios (SUVRs) of 18F-THK-5351 PET images were measured from six GM and WM regions using cerebellar GM as reference. GM and WM SUVRs and WM/GM ratios, the relationship between GM SUVR and WM/GM ratio, and correlation between SUVR and cognitive function were compared. RESULTS: In AD, both parietal GM (p < 0.001) and WM (p < 0.001) SUVRs were higher than in bvFTD. In AD and SD, the WM/GM ratio decreased as the GM SUVR increased, regardless of lobar region. In AD, memory function correlated with parietal GM (ρ = -0.74, p < 0.001) and WM (ρ = -0.53, p < 0.001) SUVR. In SD, language function correlated with temporal GM SUVR (ρ = -0.69, p = 0.006). The frontal WM SUVR was higher in bvFTD than in AD (p = 0.003) or SD (p = 0.017). The frontal WM/GM ratio was higher in bvFTD than in AD (p < 0.001). In bvFTD, the WM/GM ratio increased more prominently than the GM SUVR only in the frontal lobe (R2 = 0.026). In bvFTD, executive function correlated with frontal WM SUVR (ρ = -0.64, p = 0.014). CONCLUSIONS: Frontal WM 18F-THK5351 uptake was higher in bvFTD than in other dementias. The increase in frontal WM uptake was greater than the increase in GM uptake and correlated with executive function. This suggests that frontal lobe WM 18F-THK5351 uptake reflects neuropathological differences between bvFTD and other dementias.

Case series of post-purpuric darkness on the periorbital area after aesthetic surgery.

Periorbital hyperpigmentation (POH) is a common condition encountered in dermatology practice. POH is caused by various exogenous and endogenous factors including excessive pigmentation, postinflammatory hyperpigmentation (PIH) secondary to eczema, periorbital edema, excessive vascularity, and aging. Recently, we have experienced several patients who complained of POH with an unusual pattern. Their pigmented lesions had several features in common. The pigmentation occurred bilaterally after aesthetic surgery involving the periorbital region. Periorbital post-purpuric darkness should be distinguished from common POH. Practitioners should ask patients about history of prior aesthetic surgery and make their patients aware that the dark colors are composed of various pigments such as hemosiderin, which make treatment troublesome. Conservative management with expectations for gradual spontaneous regression or laser therapy with multiple wavelengths including 1,064-nm laser for PIH and 650 or 694-nm laser targeting heme-derived pigments may be considered as treatment options.

Topical brimonidine-assisted laser treatment for the prevention of therapy-related erythema and hyperpigmentation.

Postinflammatory hyperpigmentation (PIH) and erythema are the most common adverse effects associated with laser treatment, particularly in dark-skinned individuals. Several methods have been used to prevent or minimize these adverse effects; however, to date, no definitive precautions/strategies are known to prevent post-laser PIH and erythema. We investigated whether the topical application of the α-adrenergic receptor agonist brimonidine could reduce laser treatment-related complications such as erythema and PIH.

Treatment of post-pulsed dye laser purpura with pulsed dye laser.

The pulsed dye laser (PDL) is used for the treatment of a variety of vascular and nonvascular disorders, and its therapeutic efficacy often depends on purpura as an endpoint. However, post-PDL purpura is an undesirable side effect of treatment as it may increase patient dissatisfaction and downtime. Recent studies have suggested that repeat treatment with PDL may speed the resolution of post-procedural purpura; however, there is paucity of data on using repeat PDL treatment specifically for post-PDL purpura. We report three cases of 585 nm PDL-induced purpura treated with 595 nm PDL with clinically significant improvement. We suggest that treatment with PDL, which targets hemoglobin and its breakdown products, after initial PDL treatment may reduce post-PDL purpura.

The pinhole method using an erbium: YAG laser for the treatment of papular acne scars.

Papular acne scars are skin-colored or hypopigmented, soft and elevated lesions of the chin and trunk. Papular scars are one of the most difficult acne scars to treat. Herein, we reported two patients with papular acne scars on the chin that were successfully treated by the pinhole method using an Erbium (ER):YAG laser. Good cosmetic results were achieved in both patients. The side effects included mild, intra-, and post-procedural pain and erythema that resolved spontaneously within 2 weeks. The pinhole method with an Er:YAG laser could potentially be used as a safe and effective treatment for papular acne scars.

Absence of subchronic oral toxicity and genotoxicity of rice koji with Aspergillus terreus.

Koji products have been considered as an effective fermented food consumed in East Asia with many health benefits. Particularly, rice koji with Aspergillus terreus (RAT) has been reported to be able to prevent hyperlipidemia and hepatic steatosis through regulating cholesterol synthesis. Despite its biological activities, there is a lack of comprehensive information to give an assurance of its safety. Therefore, the objective of this study was to perform a series of toxicological studies (repeated dose oral toxicity and genotoxicity) according to test guidelines published by the Organization for Economic Cooperation and Development. Along with acute toxicity study using rats and beagle dogs, a 13-week toxicity study revealed no clear RAT-related toxic changes, including body weight, mortality, hematology, serum biochemistry, organ weight, and histopathology after oral administration at doses of 500, 1000, and 2000 mg/kg BW. The no-observed-adverse-effect level of RAT was considered to be more than 2000 mg/kg BW/day in rats of both genders. In addition, potential genotoxicity was evaluated using a standard battery of tests (Ames test, chromosome aberration assay, and micronucleus assay) which revealed that RAT showed no genotoxicity. Accordingly, these results suggest that RAT is a safe and non-toxic functional food for human consumption at proper dose.

Influences of Sr-Incorporated TiO2 Layer on the Photovoltaic Properties of Dye-Sensitized Solar Cells.

Effects of a mixed overlayer composed of TiO2 and TiSrO3 on the performance of dye-sensitized solar cells (DSSCs) were investigated. The surface of TiO2 photoelectrode formed on F-doped SnO2 (FTO) was modified by soaking it in a TiCl4:SrCl2 mixed aqueous solution with various molar ratios and then calcining to produce the TiCl4:SrCl2-treated TiO2 photoelectrode (Ti:Sr-TiO2/FTO). The highest power conversion efficiency (PCE) was obtained from DSSC with Ti:Sr(7:3)-TiO2/FTO, which was prepared from the mixed solution with the molar ratio of 7:3 (TiOl4:SrCl2). An enhancement in short-circuit photocurrent (J(sc)) and open-circuit voltage (V(oc)) of DSSC with Ti:Sr(7:3)-TiO2/FTO was achieved, compared to those of the reference device with Ti:Sr(10:0)-TiC2/FTO (i.e., TiO2-coated TiO2/FTO). The incorporation of the mixed overlayer on the nanoporous TiO2 photoelectorde led to an improvement in the electron collection efficiency by a prolonged electron lifetime, thereby increasing the J(sc) value. The increase in V(oc) value of the device with Ti:Sr(7:3)-TiO2/FTO was due to the suppression of the charge recombination between injected electrons and I3(-) ions.

Facial Pores: Definition, Causes, and Treatment Options.

BACKGROUND: Enlarged skin pores refer to conditions that present with visible topographic changes of skin surfaces. Although not a medical concern, enlarged pores are a cosmetic concern for a large number of individuals. Moreover, clear definition and possible causes of enlarged pores have not been elucidated. OBJECTIVE: To review the possible causes and treatment options for skin pores. METHODS: This article is based on a review of the medical literature and the authors' clinical experience in investigating and treating skin pores. RESULTS: There are 3 major clinical causes of enlarged facial pores, namely high sebum excretion, decreased elasticity around pores, and increased hair follicle volume. In addition, chronic recurrent acne, sex hormones, and skin care regimen can affect pore size. Given the different possible causes for enlarged pores, therapeutic modalities must be individualized for each patient. CONCLUSION: Potential factors that contribute to enlarged skin pores include excessive sebum, decreased elasticity around pores, and increased hair follicle volume. Because various factors cause enlarged facial pores, it might be useful to identify the underlying causes to be able to select the appropriate treatment.

Treatment of hesitation marks on the forearm by the pinhole method.

Scars from self-inflicted wounds, referred to as "hesitation marks," are usually linear, flat, poorly oriented, white in color, and often located on the forearm. Many patients do not undergo treatment for these due to limited available modalities. The aim of this study was to evaluate the efficacy and safety of the pinhole method using a 10,600 nm carbon dioxide (CO2) laser for treating hesitation marks on the forearm. We conducted a retrospective chart review of patients with hesitation marks treated by the pinhole method from March 2010 to April 2014. Eleven patients with hesitation marks (mean age 37.8 years; range, 23-67 years) were treated with the pinhole method over the 4-year study period. Subjects were treated via the pinhole method in one to six treatment sessions at 4- to 8-week intervals. Two blinded observers evaluated photographs taken at baseline and 3 months after the final treatment and assessed improvement using a quartile grading scale. Compared with baseline, there was mild to moderate improvement in all patients (mean score 3.0). The patient satisfaction survey revealed a mean improvement score of 2.82. The pinhole method using a CO2 laser may be an effective treatment option in patients with hesitation marks on the forearm.

Biological evaluation of new [(18) F]F-labeled synthetic amino acid derivatives as oncologic radiotracers.

The present study evaluated the tumoral uptake of the novel synthetic amino acid positron emission tomography (PET) tracers (S)-2-amino-3-(4-([(18) F]fluoromethyl)-1H-1,2,3-triazol-1-yl)propanoic acid (AMC-101), (S)-2-amino-4-(4-([(18) F]fluoromethyl)-1H-1,2,3-triazol-1-yl)butanoic acid (AMC-102), and (S)-2-amino-5-(4-([(18) F]fluoromethyl)-1H-1,2,3-triazol-1-yl)pentanoic acid (AMC-103), all of which are (S)-2-amino-(4-([(18) F]fluoromethyl)-1H-1,2,3-triazol-1-yl)alkyl acids. In vitro cellular uptake was investigated using the rat glioma cell lines 9L and C6. In vitro competitive inhibition tests were performed to identify the involvement of specific amino acid transporters. In vivo dynamic PET images of 9L xenograft tumor-bearing model mice were acquired over 2 h after AMC administration. [(18) F]FDOPA PET studies were performed with and without S-carbidopa pretreatment for comparison. All three AMCs exhibited good in vitro cell uptake through the L and alanine-serine-cysteine transporters and enabled clear tumor visualization on PET, leaving the brain devoid of the tracer. Thirty minutes after injection, the mean tumor standardized uptake values were 1.59 ± 0.05, 1.89 ± 0.27, and 1.74 ± 0.13 for AMC-101, AMC-102, and AMC-103, respectively. Although the tumor uptake values of AMCs were lower than that of [(18) F]FDOPA with S-carbidopa pretreatment, AMCs enabled higher contrast images with lower background activity compared with [(18) F]FDOPA with S-carbidopa pretreatment. Our results indicate the potential uses of these new synthetic amino acids as oncologic radiotracers.