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This study was undertaken to analyze the clinical results and complication rate of patients undergoing outpatient total joint arthroplasty by a single orthopedic group. All surgeries were performed in the practice-owned ambulatory surgery center (ASC).All patients indicated for outpatient total joint arthroplasty from 2016-2019 with complete pre and post-operative patient reported outcomes were enrolled in the study including hip, knee and partial knee replacements. Patient reported outcomes including HOOS, KOOS and VR-12 were collected at six months. Patient complication and satisfaction data was also collected.There were 1007 patients enrolled in the study. At six months, THA HOOS and VR-12 scores improved to 82.2 and 54.5/45. TKA KOOS and VR-12 scores improved to an average of 74.3 and 54.0/43.6. At six months, UKA scores improved to an average of 73.6 and 55.1/41.2. All HOOS, KOOS and VR-12 PCS scores improvements were statistically significant (p 0.001) and met MCID thresholds. A separate cohort of 1898 regionally tracked cases with comprehensive global complication data exhibited 111 complications (unplanned post-operative events generating a medical expense) including manipulation 13 (0.68%), DVT/PE 4 (0.2%), medical 45 (2.4%), wound 8 (0.4%), infection 8 (0.4%). Sixty-six outpatient cases (3.5%) experienced clinical complications requiring some form of additional treatment.Outpatient joint arthroplasty performed in the ASC is safe and effective in appropriately selected patients with complication rates that compares favorably to inpatient procedures.

Rolling circle amplification (RCA) is a powerful tool for the construction of DNA nanomaterials such as hydrogels, high-performance scaffolds and DNA nanoflowers (DNFs), hybrid materials formed of DNA and magnesium pyrophosphate. Such DNA nanomaterials have great potential in therapeutics, imaging, protein immobilisation, and drug delivery, yet limited chemistry is available to expand their functionality. Here, we present orthogonal strategies to produce densely modified RCA products and DNFs. We provide methods to selectively modify the DNA component and/or the protein cargo of these materials, thereby greatly expanding the range of chemical functionalities available to these systems. We have used our methodology to construct DNFs bearing multiple surface aptamers and peptides capable of binding to cancer cells that overexpress the HER2 oncobiomarker, demonstrating their potential for diagnostic and therapeutic applications., Graphical Abstract Graphical AbstractCombining modified dNTPs with rolling circle amplification to expand the functionality of DNA nanomaterials.

Vaccinia virus (VV) is a powerful tool for cancer treatment with the potential for tumor tropism, efficient cell-to-cell spread, rapid replication in cancer cells, and stimulation of anti-tumor immunity. It has a well-defined safety profile and is being assessed in late-stage clinical trials. However, VV clinical utility is limited by rapid bloodstream neutralization and poor penetration into tumors. These factors have often restricted its route of delivery to intratumoral or intrahepatic artery injection and may impede repeat dosing. Chemical stealthing improves the pharmacokinetics of non-enveloped viruses, but it has not yet been applied to enveloped viruses such as VV. In the present study, amphiphilic polymer was used to coat VV, leading to reduced binding of a neutralizing anti-VV antibody (81.8% of polymer-coated VV [PCVV] staining positive versus 97.1% of VV [p = 0.0038]). Attachment of anti-mucin-1 (aMUC1) targeting antibody, to give aMUC1-PCVV, enabled binding of the construct to MUC1. In high MUC1 expressing CAPAN-2 cells, infection with PCVV was reduced compared to VV, while infection was restored with aMUC1-PCVV. Pharmacokinetics of aMUC1-PCVV, PCVV, and VV were evaluated. After intravenous (i.v.) injection of 1 × 108 viral genomes (VG) or 5 × 108 VG, circulation time for PCVV and aMUC1-PCVV was increased, with ~5-fold higher circulating dose at 5 min versus VV., Graphical abstract, Oncolytic viruses, such as vaccinia virus, could be even more effective at attacking solid tumors in patients if they could be administered via the bloodstream without being neutralized by blood components. These studies show that adding a protective coat to vaccinia virus improves its stability in blood.

Chlorhexidine skin antisepsis is frequently recommended for most surgical procedures; however, it is unclear if these recommendations should apply to surgery involving traumatic contaminated wounds where povidone-iodine has previously been preferred. We aimed to compare the effect of aqueous 10% povidone-iodine versus aqueous 4% chlorhexidine gluconate on the risk of surgical site infection in patients who required surgery for an open fracture.We conducted a multiple-period, cluster-randomised, crossover trial (Aqueous-PREP) at 14 hospitals in Canada, Spain, and the USA. Eligible patients were adults aged 18 years or older with an open extremity fracture treated with a surgical fixation implant. For inclusion, the open fracture required formal surgical debridement within 72 h of the injury. Participating sites were randomly assigned (1:1) to use either aqueous 10% povidone-iodine or aqueous 4% chlorhexidine gluconate immediately before surgical incision; sites then alternated between the study interventions every 2 months. Participants, health-care providers, and study personnel were aware of the treatment assignment due to the colour of the solutions. The outcome adjudicators and data analysts were masked to treatment allocation. The primary outcome was surgical site infection, guided by the 2017 US Centers for Disease Control and Prevention National Healthcare Safety Network reporting criteria, which included superficial incisional infection within 30 days or deep incisional or organ space infection within 90 days of surgery. The primary analyses followed the intention-to-treat principle and included all participants in the groups to which they were randomly assigned. This study is registered with ClinicalTrials.gov, NCT03385304.Between April 8, 2018, and June 8, 2021, 3619 patients were assessed for eligibility and 1683 were enrolled and randomly assigned to povidone-iodine (n=847) or chlorhexidine gluconate (n=836). The trial's adjudication committee determined that 45 participants were ineligible, leaving 1638 participants in the primary analysis, with 828 in the povidone-iodine group and 810 in the chlorhexidine gluconate group (mean age 44·9 years [SD 18·0]; 629 [38%] were female and 1009 [62%] were male). Among 1571 participants in whom the primary outcome was known, a surgical site infection occurred in 59 (7%) of 787 participants in the povidone-iodine group and 58 (7%) of 784 in the chlorhexidine gluconate group (odds ratio 1·11, 95% CI 0·74 to 1·65; p=0·61; risk difference 0·6%, 95% CI -1·4 to 3·4).For patients who require surgical fixation of an open fracture, either aqueous 10% povidone-iodine or aqueous 4% chlorhexidine gluconate can be selected for skin antisepsis on the basis of solution availability, patient contraindications, or product cost. These findings might also have implications for antisepsis of other traumatic wounds.US Department of Defense, Canadian Institutes of Health Research, McMaster University Surgical Associates, PSI Foundation.

Background Triple negative breast cancer (TNBC) poses a serious clinical challenge as it is an aggressive form of the disease that lacks estrogen receptor, progesterone receptor, and ERBB2 (formerly HER2) gene amplification, which limits the treatment options. The Warburg phenotype of upregulated glycolysis in the presence of oxygen has been shown to be prevalent in TNBC. Elevated glycolysis satisfies the energy requirements of cancer cells, contributes to resistance to treatment by maintaining redox homeostasis and generating nucleotide precursors required for cell proliferation and DNA repair. Expression of the monocarboxylate transporter 1 (MCT1), which is responsible for the bidirectional transport of lactate, correlates with an aggressive phenotype and poor outcome in several cancer types, including breast cancer. In this study, 3-bromopyruvate (3BP), a lactate/pyruvate analog, was used to selectively target TNBC cells that express MCT1. Methods The cytotoxicity of 3BP was tested in MTT assays using human TNBC cell lines: BT20 (MCT1+/MCT4−), MDA-MB-23 (MCT1−/MCT4+), and BT20 in which MCT1 was knocked down (siMCT1-BT20). The metabolite profile of 3BP-treated and 3BP-untreated cells was investigated using LC-MS/MS. The extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) of BT20 and MDA-MB-231 cells treated with 3BP were measured using a Seahorse XF96 extracellular flux analyzer. The impact of ionizing radiation on cell survival, alone or in combination with 3BP pre-treatment, was evaluated using clonogenic assays. Results Metabolomic analyses showed that 3BP causes inhibition of glycolysis, disturbance of redox homeostasis, decreased nucleotide synthesis, and was accompanied by a reduction in medium acidification. In addition, 3BP potentiated the cytotoxic effect of ionizing radiation, a treatment that is frequently used in the management of TNBC. Conclusions Overall, MCT1-mediated metabolic perturbation in combination with radiotherapy is shown to be a promising strategy for the treatment of glycolytic tumors such as TNBC, overcoming the selectivity challenges of targeting glycolysis with glucose analogs.

Telomerase represents an attractive target in oncology as it is expressed in cancer but not in normal tissues. The oligonucleotide inhibitors of telomerase represent a promising anticancer strategy, although poor cellular uptake can restrict their efficacy. In this study, gold nanoparticles (AuNPs) were used to enhance oligonucleotide uptake. “match” oligonucleotides complementary to the telomerase RNA template subunit (hTR) and “scramble” (control) oligonucleotides were conjugated to diethylenetriamine pentaacetate (DTPA) for111In-labeling. AuNPs (15.5 nm) were decorated with a monofunctional layer of oligonucleotides (ON–AuNP) or a multifunctional layer of oligonucleotides, PEG(polethylene glycol)800-SH (to reduce AuNP aggregation) and the cell-penetrating peptide Tat (ON–AuNP–Tat). Match–AuNP enhanced the cellular uptake of radiolabeled oligonucleotides while retaining the ability to inhibit telomerase activity. The addition of Tat to AuNPs increased nuclear localization.111In–Match–AuNP–Tat induced DNA double-strand breaks and caused a dose-dependent reduction in clonogenic survival of telomerase-positive cells but not telomerase-negative cells. hTR inhibition has been reported to sensitize cancer cells to ionizing radiation, and111In–Match–AuNP–Tat therefore holds promise as a vector for delivery of radionuclides into cancer cells while simultaneously sensitizing them to the effects of the emitted radiation.

Understanding the intra-tumoral distribution of chemotherapeutic drugs is extremely important in predicting therapeutic outcome. Tissue mimicking gel phantoms are useful for studying drug distribution in vitro but quantifying distribution is laborious due to the need to section phantoms over the relevant time course and individually quantify drug elution. In this study we compare a bespoke version of the traditional phantom sectioning approach, with a novel confocal microscopy technique that enables dynamic in situ measurements of drug concentration. Release of doxorubicin from Drug-eluting Embolization Beads (DEBs) was measured in phantoms composed of alginate and agarose over comparable time intervals. Drug release from several different types of bead were measured. The non-radiopaque DC Bead™ generated a higher concentration at the boundary between the beads and the phantom and larger drug penetration distance within the release period, compared with the radiopaque DC Bead LUMI™. This is likely due to the difference of compositional and structural characteristics of the hydrogel beads interacting differently with the loaded drug. Comparison of in vitro results against historical in vivo data show good agreement in terms of drug penetration, when confounding factors such as geometry, elimination and bead chemistry were accounted for. Hence these methods have demonstrated potential for both bead and gel phantom validation, and provide opportunities for optimisation of bead design and embolization protocols through in vitro-in vivo comparison.

Introduction: Oncolytic virotherapy is a selective and powerful tool for cancer treatment. Studies proving the ability of oncolytic viruses (OVs) to target and rapidly kill cancer cells have led to approval of H101 and Imlygic®. Both these OVs are restricted to intratumoral administration into cancer lesions. Despite promising preclinical results, systemic delivery of OV has shown limited success in patients due to a knockdown in infectivity, as a result of rapid immune-mediated neutralization, and poor penetration into tumors. Areas covered: This review catalogs the techniques used to enhance OV delivery. Firstly, insights from clinical trials of OV provide evidence of the need for enhanced delivery strategies. Secondly, the techniques applied to overcome the challenges highlighted by clinical trial data (i.e. suboptimal pharmacokinetics, antiviral immune responses, and poor penetration into solid tumors) are reviewed. Expert opinion: For OV to gain traction and convert potential into value, researchers focussed on showing clinical and commercial viability following intratumoral injection. For the technology to mature and become applicable across a wider range of patients/cancer indications, amenability to systemic delivery is required. This may be achieved using strategies that modulate the OV by genetic or chemical means and/or that alter the physiology of target tumors.

Lyso-thermosensitive liposomes (LTSLs) are specifically designed to release chemotherapy agents under conditions of mild hyperthermia. Preclinical studies have indicated that magnetic resonance (MR)-guided focused ultrasound (FUS) systems can generate well-controlled volumetric hyperthermia using real-time thermometry. However, high-throughput clinical translation of these approaches for drug delivery is challenging, not least because of the significant cost overhead of MR guidance and the much larger volumes that need to be heated clinically. Using an ultrasound-guided extracorporeal clinical FUS device (Chongqing HAIFU, JC200) with thermistors in a non-perfused ex vivo bovine liver tissue model with ribs, we present an optimised strategy for rapidly inducing (5-15 min) and sustaining (>30 min) mild hyperthermia (ΔT

Aims: Testing ultrasound-mediated cavitation for enhanced delivery of the therapeutic antibody cetuximab to tumors in a mouse model. Methods: Tumors with strong EGF receptor expression were grown bilaterally. Cetuximab was coadministered intravenously with cavitation nuclei, consisting of either the ultrasound contrast agent Sonovue or gas-stabilizing nanoscale SonoTran Particles. One of the two tumors was exposed to focused ultrasound. Passive acoustic mapping localized and monitored cavitation activity. Both tumors were then excised and cetuximab concentration was quantified. Results: Cavitation increased tumoral cetuximab concentration. When nucleated by Sonovue, a 2.1-fold increase (95% CI 1.3- to 3.4-fold) was measured, whereas SonoTran Particles gave a 3.6-fold increase (95% CI 2.3- to 5.8-fold). Conclusions: Ultrasound-mediated cavitation, especially when nucleated by nanoscale gas-entrapping particles, can noninvasively increase site-specific delivery of therapeutic antibodies to solid tumors.

In 2019, an ‘influenza pandemic’ and ‘vaccine hesitancy’ were listed as two of the top 10 challenges to global health by the WHO. The skin is a unique vaccination site, due to its immune-rich milieu, which is evolutionarily primed to respond to challenge, and its ability to induce both humoral and cellular immunity. Vaccination into this dermal compartment offers a way of addressing both of the challenges presented by the WHO, as well as opening up avenues for novel vaccine formulation and dose-sparing strategies to enter the clinic. This review will provide an overview of the diverse range of vaccination techniques available to target the dermal compartment, as well as their current state, challenges, and prospects, and touch upon the formulations that have been developed to maximally benefit from these new techniques. These include needle and syringe techniques, microneedles, DNA tattooing, jet and ballistic delivery, and skin permeabilization techniques, including thermal ablation, chemical enhancers, ablation, electroporation, iontophoresis, and sonophoresis.

The purpose of this exploratory study was to investigate the combination of a radiopharmaceutical, nanoparticles and ultrasound (US) enhanced delivery to develop a clinically viable therapeutic strategy for tumours overexpressing the epidermal growth factor receptor (EGFR). Molecularly targeted radionuclides have great potential for cancer therapy but are sometimes associated with insufficient delivery resulting in sub-cytotoxic amounts of radioactivity being delivered to the tumour. Liposome formulations are currently used in the clinic to reduce the side effects and improve the pharmacokinetic profile of chemotherapeutic drugs. However, in contrast to non-radioactive agents, loading and release of radiotherapeutics from liposomes can be challenging in the clinical setting. US-activated cavitation agents such as microbubbles (MBs) have been used to release therapeutics from liposomes to enhance the distribution/delivery in a target area. In an effort to harness the benefits of these techniques, the development of a liposome loaded radiopharmaceutical construct for enhanced delivery via acoustic cavitation was studied. The liposomal formulation was loaded with peptide, human epidermal growth factor (HEGF), coupled to a chelator for subsequent radiolabelling with 111Indium ([111In]In3+), in a manner designed to be compatible with preparation in a radiopharmacy. Liposomes were efficiently radiolabelled (57%) within 1 h, with release of ~12% of the radiopeptide following a 20 s exposure to US-mediated cavitation in vitro. In clonogenic studies this level of release resulted in cytotoxicity specifically in cells over-expressing the epidermal growth factor receptor (EGFR), with over 99% reduction in colony survival compared to controls. The formulation extended the circulation time and changed the biodistribution compared to the non-liposomal radiopeptide in vivo, although interestingly the biodistribution did not resemble that of liposome constructs currently used in the clinic. Cavitation of MBs co-injected with liposomes into tumours expressing high levels of EGFR resulted in a 2-fold enhancement in tumour uptake within 20 min. However, owing to the poor vascularisation of the tumour model used the same level of uptake was achieved without US after 24 h. By combining acoustic-cavitation-sensitive liposomes with radiopharmaceuticals this research represents a new concept in achieving targeted delivery of radiopharmaceuticals.

The use of mRNA provides several compelling benefits. Cavitation-mediated delivery of mRNA has yet to be fully explored, especially in the context of achieving delivery of non-encapsulated, “free” mRNA. We present data that explore the relationship between cavitation and the transfer of, and protein expression from, free, fluorescently labelled mRNA. The protein expression exhibited in various cell lines in vitro was further tested in vivo, using sub-micron sized cavitation nuclei and the effects on transfection efficiency and expression time were examined. Acoustic exposure parameters were carefully selected, using a focused 0.5 MHz ultrasound transducer: pressure was varied from 0.3 to 2.1 MPa and 100–50 000 cycles at 5% duty cycle were used to achieve different cavitation regimes. A difference in expression time and transfection rate was observed between different cavitation nuclei and acoustic parameters. A luciferase reporter gene assay was used to characterise events in vitro. Expression due to cavitation-mediated delivery was further examined in vivo using the In Vivo imagining system and quantified using excised homogenised tumour tissue. These results provide us with a measurement window for maximum expression, exploration of how time points change across cell lines and lay the foundations for cavitation-mediated delivery and transfection of free mRNA.

Liver metastasis from breast cancer is associated with poor prognosis and is a major cause of early morbidity and mortality. When liver resection is not feasible, minimally invasive directed therapies are considered to attempt to prolong survival. Selective internal radiation therapy (SIRT) with yttrium-90 microspheres is a liver-directed therapy that can improve local control of liver metastases from colorectal cancer. We present a case of a patient with a ductal breast adenocarcinoma, who developed liver and bone metastasis despite extensive treatment with systemic chemotherapies. Following SIRT to the liver, after an initial response, the patient ultimately progressed in the liver after 7 months. Liver tumor histology obtained 20 months after the SIRT intervention demonstrated the presence of the resin microspheres in situ. This case report demonstrates the long-term control that may be achieved with SIRT to treat liver metastases from breast cancer that is refractory to previous chemotherapies, and the presence of microspheres in situ long-term. Keywords: Selective internal radiation therapy, SIRT, Transarterial radioembolization, Liver-directed therapy

Gold nanoparticles (GNPs) have demonstrated significant dose enhancement with kilovoltage (kV) X-rays, however, recent studies have shown inconsistent findings with megavoltage (MV) X-rays. We propose to evaluate the radiosensitization effect on U87 glioblastoma (GBM) cells in the presence of 42 nm GNPs and irradiated with a clinical 6 MV photon beam. Cytotoxicity and radiosensitization were measured using MTS and clonogenic cellular radiation sensitivity assays, respectively. The sensitization enhancement ratio was calculated for 2 Gy (SER2Gy) with GNP (100 &mu, g/mL). Dark field and MTS assays revealed high co-localization and good biocompatibility of the GNPs with GBM cells. A significant sensitization enhancement of 1.45 (p = 0.001) was observed with GNP 100 &mu, g/mL. Similarly, at 6 Gy, there was significant difference in the survival fraction between the GBM alone group (mean (M) = 0.26, standard deviation (SD) = 0.008) and the GBM plus GNP group (M = 0.07, SD = 0.05, p = 0.03). GNPs enabled radiosensitization in U87 GBM cells at 2 Gy when irradiated using a clinical platform. In addition to the potential clinical utility of GNPs, these studies demonstrate the effectiveness of a robust and easy to standardize an in-vitro model that can be employed for future studies involving metal nanoparticle plus irradiation.

Gold nanoparticles (GNPs) have demonstrated significant dose enhancement with kilovoltage (kV) X-rays however recent studies have shown inconsistent findings with megavoltage (MV) X-rays. We proposed to evaluate the radiosensitization effect in U87 glioblastoma (GBM) cells in the presence of 42 nm GNPs and irradiated with a clinical 6 MV photon beam. Cytotoxicity and radiosensitization was observed using MTS and clonogenic cellular radiation sensitivity assays respectively. Sensitization enhancement ratio was calculated for 2 Gy (SER2Gy) with GNP (100 μg/mL). Dark field and MTS assay revealed high co-localization and good biocompatibility of the GNPs with GBM cells. Significant sensitization enhancement of 1.45 (P = 0.001) was observed with GNP 100 μg/mL. Similarly, at 6 Gy there was significant difference in the survival fraction between GBM alone group (Mean (M) = 0.26, Standard Deviation (SD) = 0.008) and GBM plus GNP group (M = 0.07, SD = 0.05, P = 0.03). GNPs enable radiosensitization in U87 GBM cells at 2 Gy when irradiated using a clinical platform. In addition to the potential clinical utility of GNPs, these studies demonstrate the effectiveness of a robust and easy to standardise in-vitro model that can be employed for future studies involving metal nanoparticle plus irradiation.

The optimal clinical exploitation of viruses as gene therapy or oncolytic vectors will require them to be administered intravenously. Strategies must therefore be deployed to enable viruses to survive the harsh neutralizing environment of the bloodstream and achieve deposition within and throughout target tissues or tumor deposits. This chapter describes the genetic and chemical engineering approaches that are being developed to overcome these challenges.

The optimal clinical exploitation of viruses as gene therapy or oncolytic vectors will require them to be administered intravenously. Strategies must therefore be deployed to enable viruses to survive the harsh neutralizing environment of the bloodstream and achieve deposition within and throughout target tissues or tumor deposits. This chapter describes the genetic and chemical engineering approaches that are being developed to overcome these challenges.

Novel cancer therapeutics have less than a 12% probability of translating from bench to bedside. Unwarranted toxicity and inadequate therapeutic delivery due to uptake by clearance organs, not predicted by current preclinical methods, have contributed towards this high rate of attrition. In the present work, we propose normothermic machine perfusion of human or human-sized organs as a more predictive, closer-to-human model to investigate drug pharmacokinetics and toxicity. Over the past decade, developments in the field of organ preservation for transplantation have enabled prolonged (>12 hours) normothermic machine perfusion (NMP) of isolated porcine or human organs ex vivo, maintaining quasi-physiological haemodynamic, synthetic and metabolic function using a packed red cell perfusate with physiological oxygenation and nutrient levels at normal body temperature. This preserves physiological processes such as metabolism and drug elimination, and enables easy access to tissue, blood and excreted biological fluids, with NMP livers producing bile and NMP kidneys producing urine. We hypothesise that this will provide a physiologically relevant platform to investigate drug pharmacokinetics and toxicity. We selected a widely used small-molecule chemotherapeutic (Irinotecan hydrochloride 2mg/ml, Medac, UK) which has seen decades of clinical use and benefits from extensive clinical pharmacokinetic data. The small-molecule drug was infused into isolated porcine and human livers and kidneys, with quantification of concentration time profiles of the prodrug and its main metabolites in plasma, bile and urine over 16-24 hours of NMP. In addition to irinotecan (CPT11), three of its metabolites (APC, SN38G, SN38) were successfully detected and quantified, demonstrating peak plasma concentrations (Cmax ~ 10,000 ng/mL, 1000 ng/mL, 100 ng/g, 30 ng/g), plasma decay rates and percentages of injected dose in bile (%ID ~20%, 8%, 25%, 1%) and urine (%ID ~20%, 0.06%, 0.5%,0.1%) that are comparable to clinical data. Drug-tissue toxicity could also be adequately replicated in the NMP model. In conclusion, we have demonstrated that human-sized isolated, normothermically perfused livers and kidneys accurately represent the clinically observed pharmacokinetic and toxicity profiles of an established small-molecule therapeutic. Further model validation is ongoing for biologics and other nanomedicines which are susceptible to clearance by the mononuclear phagocytic system or are hepato- or nephrotoxic. If this proves successful, normothermic machine perfusion of isolated porcine and human organs could greatly aid the early screening of candidate therapeutics and significantly enhance the pace and success rate with which they are translated into patients. Citation Format: Tamsyn Clark, Luca Bau, Fungai Dengu, Daniel Voyce, Robert Carlisle, Peter Friend, Constantin Coussios. Predicting clinical pharmacokinetics and toxicity of current and emerging oncology therapeutics by normothermic perfusion of isolated human-sized organs [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1369.

Introduction: The successful treatment of metastatic cancer is refractory to strategies employed to treat confined, primary lesions, such as surgical resection and radiation therapy, and thus must be addressed by systemic delivery of anti-cancer agents. Conventional systemically administered chemotherapeutics are often ineffective and come with severe dose-limiting toxicities. Areas covered: This review focuses on the recent developments in systemic therapy for metastatic cancer. Firstly, the strategies employed to improve the efficacy of conventional chemotherapeutics by ‘passively’ and ‘actively’ targeting them to tumors are discussed. Secondly, recent advances in the use of biologics to better target cancer and to instigate anti-tumor immunity are reviewed. Under the label of ‘biologics’, antibody-therapies, T cell engaging therapies, oncolytic virotherapies and cell-based therapies are examined and evaluated. Expert opinion: Improving specificity of action, and engaging the immune system appear to be key goals in the development of novel or reformulated anti-cancer agents for the treatment of metastatic cancer. One of the largest areas of opportunity in this field will be the identification of robust predictive biomarkers for use in conjunction with these agents. Treatment regimens that combine an agent to elicit an immune response (such as an oncolytic virus), and an agent to potentiate/mediate that immune response (such as immune checkpoint inhibitors) are predicted to be more effective than treatment with either agent alone.

Purpose To demonstrate the feasibility and safety of using focused ultrasound planning models to determine the treatment parameters needed to deliver volumetric mild hyperthermia for targeted drug delivery without real-time thermometry. Materials and Methods This study was part of the Targeted Doxorubicin, or TARDOX, phase I prospective trial of focused ultrasound-mediated, hyperthermia-triggered drug delivery to solid liver tumors ( ClinicalTrials.gov identifier NCT02181075). Ten participants (age range, 49-68 years; average age, 60 years; four women) were treated from March 2015 to March 2017 by using a clinically approved focused ultrasound system to release doxorubicin from lyso-thermosensitive liposomes. Ultrasonic heating of target tumors (treated volume: 11-73 cm3 [mean ± standard deviation, 50 cm3 ± 26]) was monitored in six participants by using a minimally invasive temperature sensor; four participants were treated without real-time thermometry. For all participants, CT images were used with a patient-specific hyperthermia model to define focused ultrasound treatment plans. Feasibility was assessed by comparing model-prescribed focused ultrasound powers to those implemented for treatment. Safety was assessed by evaluating MR images and biopsy specimens for evidence of thermal ablation and monitoring adverse events. Results The mean difference between predicted and implemented treatment powers was -0.1 W ± 17.7 (n = 10). No evidence of focused ultrasound-related adverse effects, including thermal ablation, was found. Conclusion In this 10-participant study, the authors confirmed the feasibility of using focused ultrasound-mediated hyperthermia planning models to define treatment parameters that safely enabled targeted, noninvasive drug delivery to liver tumors while monitored with B-mode guidance and without real-time thermometry. Published under a CC BY 4.0 license. Online supplemental material is available for this article. See also the editorial by Dickey and Levi-Polyachenko in this issue.

Summary Background Previous preclinical research has shown that extracorporeal devices can be used to enhance the delivery and distribution of systemically administered anticancer drugs, resulting in increased intratumoural concentrations. We aimed to assess the safety and feasibility of targeted release and enhanced delivery of doxorubicin to solid tumours from thermosensitive liposomes triggered by mild hyperthermia, induced non-invasively by focused ultrasound. Methods We did an open-label, single-centre, phase 1 trial in a single UK hospital. Adult patients (aged ≥18 years) with unresectable and non-ablatable primary or secondary liver tumours of any histological subtype were considered for the study. Patients received a single intravenous infusion (50 mg/m 2 ) of lyso-thermosensitive liposomal doxorubicin (LTLD), followed by extracorporeal focused ultrasound exposure of a single target liver tumour. The trial had two parts: in part I, patients had a real-time thermometry device implanted intratumourally, whereas patients in part II proceeded without thermometry and we used a patient-specific model to predict optimal exposure parameters. We assessed tumour biopsies obtained before and after focused ultrasound exposure for doxorubicin concentration and distribution. The primary endpoint was at least a doubling of total intratumoural doxorubicin concentration in at least half of the patients treated, on an intention-to-treat basis. This study is registered with ClinicalTrials.gov, number NCT02181075, and is now closed to recruitment. Findings Between March 13, 2015, and March 27, 2017, ten patients were enrolled in the study (six patients in part I and four in part II), and received a dose of LTLD followed by focused ultrasound exposure. The treatment resulted in an average increase of 3·7 times in intratumoural biopsy doxorubicin concentrations, from an estimate of 2·34 μg/g (SD 0·93) immediately after drug infusion to 8·56 μg/g (5·69) after focused ultrasound. Increases of two to ten times were observed in seven (70%) of ten patients, satisfying the primary endpoint. Serious adverse events registered were expected grade 4 transient neutropenia in five patients and prolonged hospital stay due to unexpected grade 1 confusion in one patient. Grade 3–4 adverse events recorded were neutropenia (grade 3 in one patient and grade 4 in five patients), and grade 3 anaemia in one patient. No treatment-related deaths occurred. Interpretation The combined treatment of LTLD and non-invasive focused ultrasound hyperthermia in this study seemed to be clinically feasible, safe, and able to enhance intratumoural drug delivery, providing targeted chemo-ablative response in human liver tumours that were refractory to standard chemotherapy. Funding Oxford Biomedical Research Centre, National Institute for Health Research.

The treatment of cancer using nanomedicines is limited by the poor penetration of these potentially powerful agents into and throughout solid tumors. Externally controlled mechanical stimuli, such as the generation of cavitation-induced microstreaming using ultrasound (US), can provide a means of improving nanomedicine delivery. Notably, it has been demonstrated that by focusing, monitoring and controlling the US exposure, delivery can be achieved without damage to surrounding tissue or vasculature. However, there is a risk that such stimuli may disrupt the structure and thereby diminish the activity of the delivered drugs, especially complex antibody and viral-based nanomedicines. In this study, we characterize the impact of cavitation on four different agents, doxorubicin (Dox), cetuximab, adenovirus (Ad) and vaccinia virus (VV), representing a scale of sophistication from a simple small-molecule drug to complex biological agents. To achieve tight regulation of the level and duration of cavitation exposure, a “cavitation test rig” was designed and built. The activity of each agent was assessed with and without exposure to a defined cavitation regime which has previously been shown to provide effective and safe delivery of agents to tumors in preclinical studies. The fluorescence profile of Dox remained unchanged after exposure to cavitation, and the efficacy of this drug in killing a cancer cell line remained the same. Similarly, the ability of cetuximab to bind its epidermal growth factor receptor target was not diminished following exposure to cavitation. The encoding of the reporter gene luciferase within the Ad and VV constructs tested here allowed the infectivity of these viruses to be easily quantified. Exposure to cavitation did not impact on the activity of either virus. These data provide compelling evidence that the US parameters used to safely and successfully delivery nanomedicines to tumors in preclinical models do not detrimentally impact on the structure or activity of these nanomedicines.

New classes of biologically active materials, such as viruses, siRNA, antibodies and a wide range of engineered nanoparticles have emerged as potent agents for diagnosing and treating diseases, yet many of these agents fail because there is no effective route of delivery to their intended targets. Focused ultrasound and its ability to drive microbubble-seeded cavitation have been shown to facilitate drug delivery. However, cavitation is difficult to control temporally and spatially, making prediction of therapeutic outcomes deep in the body difficult. Here, we utilized passive acoustic mapping in vivo to understand how ultrasound parameters influence cavitation dynamics and to correlate spatial maps of cavitation to drug delivery. Focused ultrasound (center frequency: 0.5 MHz, peak-rarefactional pressure: 1.2 MPa, pulse length: 25 cycles or 50,000 cycles, pulse repetition interval: 0.02, 0.2, 1 or 3 s, number of pulses: 80 pulses) was applied to murine xenograft-model tumors in vivo during systemic injection of microbubbles with and without cavitation-sensitive liposomes or type 5 adenoviruses. Analysis of in vivo cavitation dynamics through several pulses revealed that cavitation was more efficiently produced at a lower pulse repetition frequency of 1 Hz than at 50 Hz. Within a pulse, inertial cavitation activity was shown to persist but reduced to 50% and 25% of its initial magnitude in 4.3 and 29.3 ms, respectively. Both through several pulses and within a pulse, the spatial distribution of cavitation was shown to change in time due to variations in microbubble distribution present in tumors. Finally, we demonstrated that the centroid of the mapped cavitation activity was within 1.33 ± 0.6 mm and 0.36 mm from the centroid location of drug release from liposomes and expression of the reporter gene encoded by the adenovirus, respectively. Thus passive acoustic mapping not only unraveled key mechanisms whereby a successful outcome is achieved, but also a predicted drug delivery outcome.

Lipid and protein-shelled microbubbles have been the mainstay of cavitation nucleation strategies for therapeutic applications for several decades. However, a growing number of therapeutic ultrasound applications require nuclei that (i) are significantly smaller in size, in order to overcome a particular biological barrier such as the leaky vasculature of tumours or the stratum corneum; (ii) offer greatly increased cavitation persistence, both during a single extended ultrasound pulse and in terms of extended circulation following intravenous administration; and (iii) have better resilience to sudden ambient pressure changes in order to enable direct injection without nuclei destruction into tissue targets via a needle and syringe. We will review a range of novel cavitation agents currently under development, including sub-micron gas-stabilizing solid particles and nanodroplets, and provide an overview of their known characteristics in terms of acoustic emissions, activation and cavitation thresholds, cavitation persistence, and circulation. Where possible, the relevant performance of these cavitation nucleation agents will be compared to microbubbles for applications ranging from drug delivery to nucleated tissue fractionation.

Sustained inertial cavitation seeded by microbubbles, sub-micron cavitation nuclei or even without any cavitation nucleation agent has been shown to enable increased delivery and penetration of drugs and vaccines across the skin, into solid tumours and across the blood-brain barrier. The safety and efficacy of these applications are typically monitored using single-element passive cavitation detectors, or more recently using multi-element arrays that enable real-time passive acoustic mapping of cavitation activity. We will provide an overview of the different types of cavitation nucleation agents which are available to use, the type and persistence of acoustic emissions that they are typically associated with, and, where possible, a direct comparison between the performance of different nucleation strategies to achieve the desired drug delivery bioeffect in the target of interest. We will then turn our attention to the presently available strategies for real-time monitoring of safety and efficacy, with specific reference to the benefits offered by the ability to achieve spatiotemporal monitoring of cavitation activity to correlate it with bioeffects in subsets of the overall region of interest.Sustained inertial cavitation seeded by microbubbles, sub-micron cavitation nuclei or even without any cavitation nucleation agent has been shown to enable increased delivery and penetration of drugs and vaccines across the skin, into solid tumours and across the blood-brain barrier. The safety and efficacy of these applications are typically monitored using single-element passive cavitation detectors, or more recently using multi-element arrays that enable real-time passive acoustic mapping of cavitation activity. We will provide an overview of the different types of cavitation nucleation agents which are available to use, the type and persistence of acoustic emissions that they are typically associated with, and, where possible, a direct comparison between the performance of different nucleation strategies to achieve the desired drug delivery bioeffect in the target of interest. We will then turn our attention to the presently available strategies for real-time monitoring of safety and efficacy, with sp...

Targeted radionuclide therapy (TRT) combines the specificity of molecular targeting with the potent cytotoxicity of ionising radiation. An emerging question is how to most effectively integrate TRT with radiosensitizing small molecules [1]. Auger electron-emitting radionuclides such as 111In are well-suited as the therapeutic radionuclide as their short-range reduces “cross fire” damage to neighbouring cells. As a novel chemical class of radiosensitizing agent, we have found ruthenium polypyridyl complexes (RPCs) that intercalate between DNA base pairs such as Ru(phen)2(tpphz)2+ (phen = 1,10 phenanthroline, tpphz = tetrapyridophenazine) act to stall replication forks and impede mitotic progression in human oesophageal cancer cells [2,3]. This dual mechanism of action results in preferential growth inhibition of rapidly-proliferating oesophageal cancer cells with elevated mitotic indices. In contrast to cisplatin and other DNA-damaging agents, relatively low DSB levels are generated in response to RPC metallo-intercalation and reduced cytotoxicity towards non-cancer cells is observed. In addition to this, treatment is able to enhance cancer cell sensitivity to IR by increasing IR-induced DNA double-strand break (DSB) damage, decreasing cell survival in a synergistic manner. Based on these discoveries, we explore how nanoparticle-mediated delivery of Ru(phen)2(tpphz)2+ and the Auger electron emitting radionuclide 111In can achieve localised cytotoxicity enhancement specifically in EGFR-overexpressing oesophageal cancer cells, thereby demonstrating both a combinational effect alongside molecular targeting for this novel combination [4]. References:[1] M. R. Gill, N. Falzone, Y. Du and K. A. Vallis, Lancet Oncol, 18, e414 (2017).[2] M. R. Gill, S. N. Harun, S. Halder, R. A. Boghozian, K. Ramadan, H. Ahmad and K. A. Vallis, Sci. Rep., 6, 31973 (2016).[3] M. R. Gill, P. J. Jarman, S. Halder, M. G. Walker, H. K. Saeed, J. A. Thomas, C. Smythe, K. Ramadan and K. A. Vallis, Chem. Sci., 9, 841 (2018).[4] M. R. Gill, J. U. Menon, P. J. Jarman, J. Owen, I. Skaripa-Koukelli, S. Able, J. A. Thomas, R. Carlisle, K. A. Vallis, Nanoscale, 10, 10596 (2018). Citation Format: Martin R. Gill, Jyothi U. Menon, Robert Carlisle, Katherine A. Vallis. Combining ruthenium metallo-intercalators and targeted radionuclide therapy for EGFR-overexpressing oesophageal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 994.

Oncolytic adenoviruses (Ads) selectively replicate within and destroy cancer cells, making them one of the most powerful therapeutics available. However, all robust responses reported to date (1–3) have relied on intratumoral injection, and until Ads can achieve efficacy following intravenous delivery their clinical use will be restricted. In particular, systemic delivery of Ads to treat metastatic cancer will require improved circulation kinetics, extravasation from the bloodstream into the tumor, and intratumoral penetration. After intravenous delivery, Ads bind antibodies, complement, and blood cells (4,5). In response, “stealthing” technologies have been developed, whereby Ads are coated with biocompatible polymers such as polyethylene glycol or N-(2-hydroxypropyl)methacrylamide (6–9). Stealthing removes natural Ad tropism and prevents binding to blood components, leading to extended circulation (10). However, by stealthing Ads to provide sufficient protection during delivery, their ability to infect cells upon arrival in tumors is often compromised. To meet this challenge, polymers can be designed to selectively degrade upon exposure to the tumor milieu. This is possible because disregulated growth of cells within tumors creates a hypoxic and low pH environment that is distinct from normal tissue (11,12). We report the development of a coating polymer that enhances circulation and also allows triggered uncoating and reactivation of Ads within tumors. Despite benefiting from the enhanced permeability retention effect (13), the passage of stealthed Ads from the bloodstream into tumors is still suboptimal, with less than 0.1% of dose achieving deposition in the tumor (4). Furthermore, the intratumoral distribution of Ads remains exclusively perivascular, and without penetration deep into the tumor, the therapeutic effect is restricted to a small proportion of its mass. Such limitations are shared by other therapeutics, such as drug–polymer conjugates and liposomes (14–17). In response, external stimuli have been applied to improve uptake into and spread through tumors (18–21). We feel that focused ultrasound is the safest and most clinically applicable of these strategies. Indeed, our in vitro studies have shown that ultrasound can provide a powerful stimulus to propel Ads deep into tumor-mimicking material (22). To achieve these effects, Ads were coadministered with a microbubble formulation (SonoVue [SV]), which provided nuclei for the initiation of a phenomenon known as inertial cavitation. This term describes the expansion, contraction, and violent collapse of a bubble in response to ultrasound, which creates microstreaming and shock waves. Such events can be used to move macromolecules more than 200 µm (21). The use of microbubbles and ultrasound to improve Ad delivery to tumors is ideal because the ultrasound pressures required are modest and clinically applicable and the inertial cavitation events created are targetable and produce distinct nonharmonic emissions that can be mapped, providing valuable feedback on the success of the procedure (23). We have improved the efficacy of Ads by combining stealthing and ultrasound to overcome their poor pharmacokinetics and limited extravasation and penetration into the tumor.

Powder-injectors use gas propulsion to deposit lyophilised drug or vaccine particles in the epidermal and sub epidermal layers of the skin. We prepared dry-powder (Tg = 45.2 ± 0.5°C) microparticles (58.1 μm) of a MenY-CRM197 glyconjugate vaccine (0.5% wt.) for intradermal needle-free powder injection (NFPI). SFD used ultrasound atomisation of the liquid vaccine-containing excipient feed, followed by lyophilisation above the glass transition temperature (Tg’ = − 29.9 ± 0.3°C). This resulted in robust particles (density~ 0.53 ±0.09 g/cm3) with a narrow volume size distribution (mean diameter 58.1 μm, and span = 1.2), and an impact parameter (ρvr ~ 11.5 kg/m·s) sufficient to breach the Stratum corneum (sc). The trehalose, manitol, dextran (10 kDa), dextran (150 kDa) formulation, or TMDD (3:3:3:1), protected the MenY-CRM197 glyconjugate during SFD with minimal loss, no detectable chemical degradation or physical aggregation. In a capsular group Y Neisseria meningitidis serum bactericidal assay (SBA) with human serum complement, the needle free vaccine, which contained no alum adjuvant, induced functional protective antibody responses in vivo of similar magnitude to the conventional vaccine injected by hypodermic needle and syringe and containing alum adjuvant. These results demonstrate that needle-free vaccination is both technically and immunologically valid, and could be considered for vaccines in development.