A first-in-class dual-chelator theranostic agent designed for use with imaging-therapy radiometal pairs of different elements.

A covalent adduct of DFOB and DOTA separated by a l-lysine residue (DFOB-l-Lys-N 6-DOTA) exhibited remarkable regioselective metal binding, with {1H}-13C NMR spectral shifts supporting Zr(iv) coordinating to the DFOB unit, and Lu(iii) coordinating to the DOTA unit. This first-in-class, dual-chelator theranostic design could enable the use of imaging-therapy radiometal pairs of different elements, such as 89Zr for positron emission tomography (PET) imaging and 177Lu for low-energy ß--particle radiation therapy. DFOB-l-Lys-N 6-DOTA was elaborated with an amine-terminated polyethylene glycol extender unit (PEG4) to give DFOB-N 2-(PEG4)-l-Lys-N 6-DOTA (compound D2) to enable installation of a phenyl-isothiocyanate group (Ph-NCS) for subsequent monoclonal antibody (mAb) conjugation (mAb = HuJ591). D2-mAb was radiolabeled with 89Zr or 177Lu to produce [89Zr]Zr-D2-mAb or [177Lu]Lu-D2-mAb, respectively, and in vivo PET/CT imaging and in vivo/ex vivo biodistribution properties measured with the matched controls [89Zr]Zr-DFOB-mAb or [177Lu]Lu-DOTA-mAb in a murine LNCaP prostate tumour xenograft model. The 89Zr-immuno-PET imaging function of [89Zr]Zr-D2-mAb and [89Zr]Zr-DFOB-mAb showed no significant difference in tumour accumulation at 48 or 120 h post injection. [89Zr]Zr-D2-mAb and [177Lu]Lu-D2-mAb showed similar ex vivo biodistribution properties at 120 h post-injection. Tumour uptake of [177Lu]Lu-D2-mAb shown by SPECT/CT imaging at 48 h and 120 h post-injection supported the therapeutic function of D2, which was corroborated by similar therapeutic efficacy between [177Lu]Lu-D2-mAb and [177Lu]Lu-DOTA-mAb, both showing a sustained reduction in tumour volume (>80% over 65 d) compared to vehicle. The work identifies D2 as a trifunctional chelator that could expand capabilities in mixed-element radiometal theranostics to improve dosimetry and the clinical outcomes of molecularly targeted radiation.

In-hospital post-operative fever after posterior spinal fusion for neuromuscular scoliosis in non-ambulatory cerebral palsy patients: is there value for clinical workup for an isolated fever?

PURPOSE: Children with neuromuscular scoliosis (NMS) resultant to cerebral palsy (CP) are at a heightened risk for complications following surgical treatment. These children have a reported 22-64% rate of post-operative fever development, and additional fever workup has been shown to have limited clinical utility. However, this has yet to be investigated in the setting of an accelerated discharge (AD) pathway. METHODS: A retrospective review of children with non-ambulatory CP treated at 2 centers with posterior spinal fusion (PSF) for NMS was performed. One institution uses a standardized AD post-operative pathway for NMS patients, whereas the second institution had no standard pathway. A post-operative fever was defined as temperature > 38.5 °C. Target outcome variables included the development of a fever as well as re-admission within 90 days of surgery. RESULTS: A total of 122 non-ambulatory children were identified (82% GMFCS V, mean 14.3 ± 3.4 years at surgery). A post-operative fever was documented in 75.4% of patients (N = 92) and all additional culture studies reported negative results. Children admitted to the PICU were more likely to undergo a fever workup (P < 0.001) and more likely to receive additional or extended antibiotic therapy (P < 0.001). Children treated at the AD pathway had a significantly lower rate of PICU admission (P < 0.001). Post-operative PICU admission was associated with a post-operative fever (49.5% vs 25%, P = 0.03). CONCLUSION: Non-ambulatory CP children with NMS undergoing PSF have a 75.4% rate of developing early post-operative fevers. Reflexive fever work-ups provided limited clinical utility while increasing the hospital length of stay and potentially exposing patients to antibiotic-related complications.

Representation and Race in Adolescent Idiopathic Scoliosis Research: Disparities in Curve Magnitude and Follow-Up.

STUDY DESIGN: Prospective Cohort Study. OBJECTIVE: The present study aims to determine if the racial representation of patients enrolled in a large prospective scoliosis registry is reflective of the general United States population. Further, we studied whether there was an association between race, pre-operative parameters, outcomes and loss to follow-up. METHODS: Prospectively collected data for patients who underwent spinal fusion for adolescent idiopathic scoliosis (AIS) was reviewed, including self-reported race/ethnicity. The U.S. pediatric population and U.S. patients enrolled in the prospective registry were compared. The data obtained was analyzed for variations between races, for pre-operative variables and follow-up. RESULTS: Of the 2210 included patients in the registry 66% of patients reported as White, while 52% of the 2018 U.S. pediatric population reported as White. 15% of the registry reported as Hispanic/Latino compared to 22% of the U.S. pediatric population, 13% Black compared to 14% of the U.S. pediatric population, and 4% Asian compared to 5% of the U.S. pediatric population. Asian and White patients had statistically significant higher 2-year follow-up in all but one of six enrollment sites (P < 0.001). Native American, Other, and Hispanic/Latino patients had the highest BMIs. Native American and Black patients had the highest pre-op thoracic Cobb angles. Pre-op ages of Black, Hispanic, and Native American patients were statistically lower (P < 0.01). CONCLUSION: This study demonstrates the association between race and patient follow-up and pre-operative factors in patients who underwent surgery for AIS. Black, Native American, and Hispanic populations were underrepresented both at pre-op and follow-up when compared to their relative proportion in the U.S. pediatric population.

Mitigating the Effects of Persistent Antipolymer Immune Reactions in Nanomedicine: Evaluating Materials-Based Approaches Using Molecular Imaging.

Poly(ethylene glycol) (PEG) is a hydrophilic polymer ubiquitously used in both medical and nonmedical goods. Recent debate surrounding the observed stimulation of immune responses against PEG has spurred the development of materials that may be suitable replacements for this common polymeric component. The underlying view is that these alternative materials with comparable physicochemical properties can overcome the unfavorable and unpredictable effects of antibody-mediated clearance by being chemically, and therefore antigenically, distinct from PEG. However, this hypothesis has not been thoroughly tested in any defined manner, and the immune response observed against PEG has not been rigorously investigated within the context of these emerging materials. Consequently, it remains unclear whether immunity-mediated discrimination between polymeric entities even occurs in vivo and, if this is the case, how it may be exploited. In this study, we utilize positron emission tomography-computed tomography molecular imaging in mice immunized to develop specific antibody responses to PEG and an alternative polymer in order to visualize and quantify the influence of antipolymer antibodies on the biodistribution of synthetic polymers in vivo as a function of immunization status. Under the conditions of this experiment, mice could be primed to exhibit both innate and adaptive immunity to all of the polymer systems to which they were exposed. We demonstrate that alternating between chemically disparate polymers is a viable approach to extend their efficacy when antipolymer humoral immune responses arise.

Transition Metal Complexes with Appended Benzimidazole Groups for Sensing Dihydrogenphosphate.

Four new complexes [Ru(bpy)2(bbib)](PF6)2, [Ru(phen)2(bbib)](PF6)2, [Re(CO)3(bbib)(py)](PF6) and [Ir(ppy)2(bbib)](PF6) [where bbib = 4,4'-bis(benzimidazol-2-yl)-2,2'-bipyridine] have been prepared and their photophysical properties determined. Their behaviour has been studied with a variety of anions in acetonitrile, DMSO and 10% aquated DMSO. Acetate and dihydrogenphosphate demonstrate a redshift in the bbib ligand associated absorptions suggesting that the ligand is strongly interacting with these anions. The 3MLCT emissive state is sensitive to the introduction of small quantities of anion (sub-stoichiometric quantities) and significant quenching is typically observed with acetate, although this is less pronounced in the presence of water. The emissive behaviour with dihydrogenphosphate is variable, showing systematic changes as anion concentration increases with several distinct interactions evident . 1H NMR and 31P NMR titrations in a 10% D2O - D6-DMSO mixture suggest that with dihydrogenphosphate, the imidazole group able to act as both a proton acceptor and donor. It appears that all four complexes can form a {[complex]2-H2PO4} "dimer", a one-to-one species (which the X-ray crystallography study suggests is dimeric in the solid-state), and a complex with a combined bis(dihydrogenphosphate) complex anion. The speciation relies on complex equilibria dependent on several factors including the complex charge, the hydrophobicity of the associated ligands, and the solvent.

Multifunctional Fluoropolymer-Engineered Magnetic Nanoparticles to Facilitate Blood-Brain Barrier Penetration and Effective Gene Silencing in Medulloblastoma.

Patients with brain cancers including medulloblastoma lack treatments that are effective long-term and without side effects. In this study, a multifunctional fluoropolymer-engineered iron oxide nanoparticle gene-therapeutic platform is presented to overcome these challenges. The fluoropolymers are designed and synthesized to incorporate various properties including robust anchoring moieties for efficient surface coating, cationic components to facilitate short interference RNA (siRNA) binding, and a fluorinated tail to ensure stability in serum. The blood-brain barrier (BBB) tailored system demonstrates enhanced BBB penetration, facilitates delivery of functionally active siRNA to medulloblastoma cells, and delivers a significant, almost complete block in protein expression within an in vitro extracellular acidic environment (pH 6.7) - as favored by most cancer cells. In vivo, it effectively crosses an intact BBB, provides contrast for magnetic resonance imaging (MRI), and delivers siRNA capable of slowing tumor growth without causing signs of toxicity - meaning it possesses a safe theranostic function. The pioneering methodology applied shows significant promise in the advancement of brain and tumor microenvironment-focused MRI-siRNA theranostics for the better treatment and diagnosis of medulloblastoma.

A New Look at Vertebral Body Tethering (VBT): Through the Modified Clavien-Dindo-Sink (mCDS) Classification.

INTRODUCTION: Anterior vertebral body tethering (AVBT) is increasingly popular as an option for surgical treatment of idiopathic scoliosis (IS). While the technology remains new, it is important for families and patients to be able to compare it to the current standard of care, posterior spinal fusion (PSF). The purpose of this study is to describe the complication rate of AVBT in IS using the mCDS and to compare it to the recently reported complication rate of PSF in IS. METHODS: A multicenter pediatric spine deformity database was queried for all idiopathic scoliosis patients who underwent vertebral body tethering. There were 171 patients with a minimum 9-month follow-up included in this study. Complications were retrospectively graded by 2 attending pediatric spine surgeons using the mCDS classification system. RESULTS: Data from 171 patients with idiopathic scoliosis was available for analysis, with 156/171 (91%) of patients being female and an average age of 12.2 years old at surgery. There were 156 thoracic tethers (1 with an LIV below L2), 5 lumbar tethers, 9 staged double tethers, and only 1 patient with same-day double tether. Fifty-five (55) (32%) patients experienced a total of 69 complications. The most common complication type for VBT by mCDS was Grade IIIb, encompassing 29/69 (42%) of complications. The second most frequent complication grade was Grade I at 23/69 (33%). Thirty-four (34) out of 69 (49%) of the VBT complications reported required either procedural/surgical intervention or admission to the ICU. CONCLUSIONS: This is the first study to directly compare the complication profile of VBT to PSF using the mCDS. Forty-nine percent (49%) of the VBT complications reported were at least Grade III, while only 7% of complications in the control PSF cohort from the literature were Grade III or higher. The mCDS complication classification brings light to the early learning experience of a new technique compared to the widely accepted standard of PSF for IS. LEVEL OF EVIDENCE: III - Retrospective comparative study.

Double major curvature treated with vertebral body tethering of both curves: how do outcomes compare to posterior spinal fusion?

PURPOSE: Vertebral body tethering (VBT) is a non-fusion alternative to posterior spinal fusion (PSF). There have been few reports on VBT of two curvatures. We aim to compare the radiographic outcomes between VBT and PSF in patients with double curvatures in which both curves were instrumented. METHODS: 29 AIS patients matched by Lenke, age (± 2 years), triradiate cartilage closure status, major Cobb angle (± 8°), and T5-T12 kyphosis (± 10°). Variables were compared using Wilcoxon rank-sum tests, Student's t tests, and chi-Square. Clinical success was defined as major curve < 35°. RESULTS: Group baseline demographics were similar. Major thoracic (T) curve types had significantly better major (VBT 51.5 ± 7.9° to 31.6 ± 12.0° [40%] vs. PSF 54.3 ± 7.4° to 17.4 ± 6.5° [68%]; p = 0.0002) and secondary curve correction in the PSF group. 71% of major T VBT patients were clinically successful versus 100% of PSF. Major thoracolumbar (TL) curve types experienced comparable major (VBT 52.3 ± 7.0° to 18.3 ± 11.4° (65%) vs. PSF 53.0 ± 5.2° to 23.8 ± 10.9° (56%); p = 0.2397) and secondary curve correction. 92% of major TL VBT patients were clinically successful versus 75% in the PSF group. There was no difference in T5-12 kyphosis or lumbar lordosis between groups for any curve type. There were 4 patients (13.8%) with major complications in the VBT group compared to 0 (0%) in the PSF. CONCLUSION: Patients with double major AIS who underwent VBT with major T curve types had less correction than PSF; however, those with major TL curves experienced similar radiographic outcomes regardless of procedure. Complications were greater for VBT.

Regional Anesthesia as an Alternative to Procedural Sedation for Forearm Fracture Reductions in the Pediatric Emergency Department.

BACKGROUND: Pediatric forearm fractures are common injuries in the pediatric emergency department (PED). Pediatric procedural sedation (PPS) is often required for forearm fracture reductions and pain control for casting. Bier blocks and hematoma blocks are types of regional anesthesia (RA) procedures that can be performed as a potential alternative to PPS. OBJECTIVE: The objective of this study is to compare the safety of RA with that of PPS. We hypothesized that RA has a safety profile that is equal or superior to PPS as well as a shorter duration of treatment in the PED. METHODS: Pediatric emergency department encounters in patients presenting with a diagnosis of radius fracture, ulna fracture, distal "both-bone" fracture, Monteggia fracture, and/or Galeazzi fracture were included. Outcomes of interest included patient adverse events (AEs), sedation medications used, PED duration of treatment (arrival time to disposition time), sedation failures, and reduction failures. RESULTS: Propensity matching was performed resulting in 632 well-matched RA-PPS pairs. The PPS cohort had 13% of encounters with at least 1 AE compared with 0.2% in the RA cohort, P < 0.001. The most common AE in the PPS group was hypoxia (9.8%), and the only AE in the RA group was an intravenous infiltrate (0.16%). Within the matched cohorts, PPS required more medications than RA (100% vs 60%, P < 0.001). Ketamine alone was more commonly used in the PPS group than the RA group (86% vs 0.2%, P < 0.001). Propofol was used only in the PPS group. The average duration of treatment was 205 (SD, 81) minutes in the PPS group and 178 (SD, 75) minutes in the RA group ( P < 0.001). There were no reduction failures in either group. CONCLUSIONS: Bier blocks and hematoma blocks are an acceptable alternative to PPS for children requiring forearm reductions. The AE rate is low and the reduction success rate is high. Duration of treatment in the PED is shorter for patients receiving RA compared with PPS.

The Effect of Implant Density on Adolescent Idiopathic Scoliosis Fusion: Results of the Minimize Implants Maximize Outcomes Randomized Clinical Trial.

BACKGROUND: Severe adolescent idiopathic scoliosis (AIS) can be treated with instrumented fusion, but the number of anchors needed for optimal correction is controversial. METHODS: We conducted a multicenter, randomized study that included patients undergoing spinal fusion for single thoracic curves between 45° and 65°, the most common form of operatively treated AIS. Of the 211 patients randomized, 108 were assigned to a high-density screw pattern and 103, to a low-density screw pattern. Surgeons were instructed to use ≥1.8 implants per spinal level fused for patients in the high-implant-density group or ≤1.4 implants per spinal level fused for patients in the low-implant-density group. The primary outcome measure was the percent correction of the coronal curve at the 2-year follow-up. The power analysis for this trial required 174 patients to show equivalence, defined as a 95% confidence interval (CI) within a ±10% correction margin with a probability of 90%. RESULTS: In the intention-to-treat analysis, the mean percent correction of the coronal curve was equivalent between the high-density and low-density groups at the 2-year follow-up (67.6% versus 65.7%; difference, -1.9% [95% CI: -6.1%, 2.2%]). In the per-protocol cohorts, the mean percent correction of the coronal curve was also equivalent between the 2 groups at the 2-year follow-up (65.0% versus 66.1%; difference, 1.1% [95% CI: -3.0%, 5.2%]). A total of 6 patients in the low-density group and 5 patients in the high-density group required reoperation (p = 1.0). CONCLUSIONS: In the setting of spinal fusion for primary thoracic AIS curves between 45° and 65°, the percent coronal curve correction obtained with use of a low-implant-density construct and that obtained with use of a high-implant-density construct were equivalent. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Targeted Hyperbranched Nanoparticles for Delivery of Doxorubicin in Breast Cancer Brain Metastasis.

Breast cancer brain metastases (BM) are associated with a dismal prognosis and very limited treatment options. Standard chemotherapy is challenging in BM patients because the high dosage required for an effective outcome causes unacceptable systemic toxicities, a consequence of poor brain penetration, and a short physiological half-life. Nanomedicines have the potential to circumvent off-target toxicities and factors limiting the efficacy of conventional chemotherapy. The HER3 receptor is commonly expressed in breast cancer BM. Here, we investigate the use of hyperbranched polymers (HBP) functionalized with a HER3 bispecific-antibody fragment for cancer cell-specific targeting and pH-responsive release of doxorubicin (DOX) to selectively deliver and treat BM. We demonstrated that DOX-release from the HBP carrier was controlled, gradual, and greater in endosomal acidic conditions (pH 5.5) relative to physiologic pH (pH 7.4). We showed that the HER3-targeted HBP with DOX payload was HER3-specific and induced cytotoxicity in BT474 breast cancer cells (IC50: 17.6 µg/mL). Therapeutic testing in a BM mouse model showed that HER3-targeted HBP with DOX payload impacted tumor proliferation, reduced tumor size, and prolonged overall survival. HER3-targeted HBP level detected in ex vivo brain samples was 14-fold more than untargeted-HBP. The HBP treatments were well tolerated, with less cardiac and oocyte toxicity compared to free DOX. Taken together, our HER3-targeted HBP nanomedicine has the potential to deliver chemotherapy to BM while reducing chemotherapy-associated toxicities.

An immunomodulating peptide with potential to suppress tumour growth and autoimmunity.

Cancers and autoimmune diseases commonly co-exist and immune checkpoint inhibitor therapy (ICI) exacerbates autoimmune pathologies. We recently described a lipidic peptide, designated IK14004, that promotes expansion of immunosuppressive T regulatory (Treg) cells and uncouples interleukin-2 from interferon-gamma production while activating CD8+ T cells. Herein, we report IK14004-mediated inhibition of Lewis lung cancer (LLC) growth and re-invigoration of splenocyte-derived exhausted CD4+ T cells. In human immune cells from healthy donors, IK14004 modulates expression of the T cell receptor α/ß subunits, induces Type I IFN expression, stimulates natural killer (NK) cells to express NKG2D/NKp44 receptors and enhances K562 cytotoxicity. In both T and NK cells, IK14004 alters the IL-12 receptor ß1/ß2 chain ratio to favour IL-12p70 binding. Taken together, this novel peptide offers an opportunity to gain further insight into the complexity of ICI immunotherapy so that autoimmune responses may be minimised without promoting tumour evasion from the immune system.

Exploring the impact of severity in hepatic fibrosis disease on the intrahepatic distribution of novel biodegradable nanoparticles targeted towards different disease biomarkers.

Nanoparticle-based drug delivery systems (DDS) have shown promising results in reversing hepatic fibrosis, a common pathological basis of chronic liver diseases (CLDs), in preclinical animal models. However, none of these nanoparticle formulations has transitioned to clinical usage and there are currently no FDA-approved drugs available for liver fibrosis. This highlights the need for a better understanding of the challenges faced by nanoparticles in this complex disease setting. Here, we have systematically studied the impact of targeting strategy, the degree of macrophage infiltration during fibrosis, and the severity of fibrosis, on the liver uptake and intrahepatic distribution of nanocarriers. When tested in mice with advanced liver fibrosis, we demonstrated that the targeting ligand density plays a significant role in determining the uptake and retention of the nanoparticles in the fibrotic liver whilst the type of targeting ligand modulates the trafficking of these nanoparticles into the cell population of interest - activated hepatic stellate cells (aHSCs). Engineering the targeting strategy indeed reduced the uptake of nanoparticles in typical mononuclear phagocyte (MPS) cell populations, but not the infiltrated macrophages. Meanwhile, additional functionalization may be required to enhance the efficacy of DDS in end-stage fibrosis/cirrhosis compared to early stages.

An immunomodulating peptide to counteract solar radiation-induced immunosuppression and DNA damage.

Ultraviolet radiation (UVR) induces immunosuppression and DNA damage, both of which contribute to the rising global incidence of skin cancer including melanoma. Nucleotide excision repair, which is activated upon UVR-induced DNA damage, is linked to expression of interleukin-12 (IL-12) which serves to limit immunosuppression and augment the DNA repair process. Herein, we report an immunomodulating peptide, designated IK14800, that not only elicits secretion of IL-12, interleukin-2 (IL-2) and interferon-gamma (IFN-γ) but also reduces DNA damage in the skin following exposure to UVR. Combined with re-invigoration of exhausted CD4+ T cells, inhibition of UVR-induced MMP-1 release and suppression of B16F10 melanoma metastases, IK14800 offers an opportunity to gain further insight into mechanisms underlying the development and progression of skin cancers.

RAFT Polymer-Antibody Conjugation: Squaramide Ester Chemistry Leads to Conjugates with a Therapeutic Anti-EGFR Antibody with Full Retention of Activity and Increased Tumor Uptake In Vivo.

Covalent conjugation of a biologically stable polymer to a therapeutic protein, e.g., an antibody, holds many benefits such as prolonged plasma exposure of the protein and improved tumor uptake. Generation of defined conjugates is advantageous in many applications, and a range of site-selective conjugation methods have been reported. Many current coupling methods lead to dispersity in coupling efficiencies with subsequent conjugates of less-well-defined structure, which impacts reproducibility of manufacture and ultimately may impact successful translation to treat or image diseases. We explored designing stable, reactive groups for polymer conjugation reactions that would lead to conjugates through the simplest and most abundant residue on most proteins, the lysine residue, yielding conjugates in high purity and demonstrating retention of mAb efficacy through surface plasmon resonance (SPR), cell targeting, and in vivo tumor targeting. We utilized squaric acid diesters as coupling agents for selective amidation of lysine residues and were able to selectively conjugate one, or two, high-molecular-weight polymers to a therapeutically relevant antibody, 528mAb, that subsequently retained full binding specificity. Water-soluble copolymers of N-(2-hydroxypropyl) methacrylamide (HPMA) and N-isopropylacrylamide (NIPAM) were prepared by Reversible Addition-Fragmentation chain-Transfer (RAFT) polymerization and we demonstrated that a dual-dye-labeled antibody-RAFT conjugate (528mAb-RAFT) exhibited effective tumor targeting in model breast cancer xenografts in mice. The combination of the precise and selective squaric acid ester conjugation method, with the use of RAFT polymers, leads to a promising strategic partnership for improved therapeutic protein-polymer conjugates having a very-well-defined structure.

Machine Learning for Benchmarking Adolescent Idiopathic Scoliosis Surgery Outcomes.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: The aim of this study was to design a risk-stratified benchmarking tool for adolescent idiopathic scoliosis (AIS) surgeries. SUMMARY OF BACKGROUND DATA: Machine learning (ML) is an emerging method for prediction modeling in orthopedic surgery. Benchmarking is an established method of process improvement and is an area of opportunity for ML methods. Current surgical benchmark tools often use ranks and no "gold standards" for comparisons exist. MATERIALS AND METHODS: Data from 6076 AIS surgeries were collected from a multicenter registry and divided into three datasets: encompassing surgeries performed (1) during the entire registry, (2) the past 10 years, and (3) during the last 5 years of the registry. We trained three ML regression models (baseline linear regression, gradient boosting, and eXtreme gradient boosted) on each data subset to predict each of the five outcome variables, length of stay (LOS), estimated blood loss (EBL), operative time, Scoliosis Research Society (SRS)-Pain and SRS-Self-Image. Performance was categorized as "below expected" if performing worse than one standard deviation of the mean, "as expected" if within 1 SD, and "better than expected" if better than 1 SD of the mean. RESULTS: Ensemble ML methods classified performance better than traditional regression techniques for LOS, EBL, and operative time. The best performing models for predicting LOS and EBL were trained on data collected in the last 5 years, while operative time used the entire 10-year dataset. No models were able to predict SRS-Pain or SRS-Self-Image in any useful manner. Point-precise estimates for continuous variables were subject to high average errors. CONCLUSIONS: Classification of benchmark outcomes is improved with ensemble ML techniques and may provide much needed case-adjustment for a surgeon performance program. Precise estimates of health-related quality of life scores and continuous variables were not possible, suggesting that performance classification is a better method of performance evaluation.

Development and Validation of a Targeted Treatment for Brain Tumors Using a Multi-Drug Loaded, Relapse-Resistant Polymeric Theranostic.

This study aimed to develop a multifunctional polymer platform that could address the issue of treatment resistance when using conventional chemotherapeutics to treat glioblastoma (GBM). An antibody-conjugated, multi-drug loaded hyperbranched polymer was developed that provided a platform to evaluate the role of targeted nanomedicine treatments in overcoming resistant GBM by addressing the various complications with current clinically administered formulations. The polymer was synthesized via reversible addition fragmentation chain transfer polymerization and included the clinical first-line alkylating agent temozolomide (TMZ) which was incorporated as a polymerizable monomer, poly (ethylene glycol) (PEG) units to impart biocompatibility and enable conjugation with αPEG-αEphA2 bispecific antibody (αEphA2 BsAb) for tumor targeting, and hydrazide moieties for attachment of a secondary drug which allows exploration of synergistic therapies. To overcome the resistance to TMZ, the O6 alkylguanine DNA alkyltransferase (AGT, DNA repair protein) inhibitor, dialdehyde O6 benzylguanine (DABG) was subsequently conjugated to the polymer via an acid labile hydrazone linker to facilitate controlled release under conditions encountered within the tumor microenvironment. The prolonged degradation half-life (4-5 h) of the polymer conjugated TMZ in vitro offered a potential avenue to overcome the inability to deliver these drugs in combination at therapeutic doses. Although only 20% of DABG could be released within the studied timeframe (192 h) under conditions mimicking the acidic nature of the tumor environment, cytotoxicity evaluation using cell assays confirmed the improved therapeutic efficacy toward resistant GBM cells after attaching DABG to the polymer delivery vehicle. Of note, when the polymeric delivery vehicle was specifically targeted to receptors (Ephrin A2) on the surface of the GBM cells using our in-house developed EphA2 specific BsAb, the dual-drug-loaded polymer exhibited an improved therapeutic effect on TMZ-resistant cells compared to the free drug combination. Both in vitro and in vivo targeting studies showed high uptake of the construct to GBM tumors with an upregulated EphA2 receptor (T98G and U251) compared to a tumor that had low expression (U87MG), where a dual tumor xenograft model was used to demonstrate the enhanced accumulation in tumor tissue in vivo. Despite the synthetic challenges of developing systems to effectively deliver controlled doses of TMZ and DABG, these studies highlight the potential benefit of this formulation for delivering multi-drug combinations to resistant GBM tumor cells and offer a platform for future optimization in therapeutic studies.

SRS-22r Self-Image After Surgery for Adolescent Idiopathic Scoliosis at 10-year Follow-up.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To examine SRS-Self Image scores at up to 10 years after surgery for adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Self-image is complex with implications for surgical and patient-reported outcomes after AIS surgery. Surgically modifiable factors that impact self-image are inconsistently reported in the literature with few longer-term reports. We examined the rate and durability of self-image improvement. MATERIALS AND METHODS: An AIS registry was queried for patients with up to 10 years of follow-up after AIS surgery. A mixed effects model estimated change in SRS-22 Self Image from baseline to 6 weeks, 1 year, 2 years, 5 years, and 10 years. All enrolled patients contributed data to the mixed effects models. A sub-analysis of patients with 1-year and 10-year follow-up evaluated worsening/static/improved SRS-22 Self Image scores examined stability of scores over that timeline. Baseline demographic data and 1-year deformity magnitude data were compared between groups using parametric and nonparametric tests as appropriate. RESULTS: Data from 4608 patients contributed data to the longitudinal model; 162 had 1-year and 10-year data. Mean SRS-Self Image improvement at 10-year follow-up was 1.0 (95% CI: 0.9-1.1) point. No significant changes in Self-Image domain scores were estimated from 1-year to 10-year (all P >0.05) postoperative. Forty (25%) patients had SRS-Self Image worsening from 1 year to 10 years, 36 (22%) improved, and 86 (53%) were unchanged. Patients who worsened over 10 years had lower SRS-Self Image at baseline than those unchanged at enrollment (3.3 vs. 3.7, P =0.007). Neither radiographic parameters nor SRS-Mental Health were different at baseline for the enrolled patients. CONCLUSION: Ten years after surgery, 75% of patients reported similar or better SRS-Self Image scores than one year after surgery. Nearly 25% of patients reported worsening self-image at 10 years. Patients who worsened had lower baseline SRS-Self Image scores, without radiographic or mental health differences at baseline or follow-up.

Self-cyclisation as a general and efficient platform for peptide and protein macrocyclisation.

Macrocyclisation of proteins and peptides results in a remarkable increase in structural stability, making cyclic peptides and proteins of great interest in drug discovery-either directly as drug leads or as in the case of cyclised nanodiscs (cNDs), as tools for studies of trans-membrane receptors and membrane-active peptides. Various biological methods have been developed that are capable of yielding head-to-tail macrocyclised products. Recent advances in enzyme-catalysed macrocyclisation include discovery of new enzymes or design of new engineered enzymes. Here, we describe the engineering of a self-cyclising "autocyclase" protein, capable of performing a controllable unimolecular reaction for generation of cyclic biomolecules in high yield. We characterise the self-cyclisation reaction mechanism, and demonstrate how the unimolecular reaction path provides alternative avenues for addressing existing challenges in enzymatic cyclisation. We use the method to produce several notable cyclic peptides and proteins, demonstrating how autocyclases offer a simple, alternative way to access a vast diversity of macrocyclic biomolecules.

Efficient delivery of Temozolomide using ultrasmall large-pore silica nanoparticles for glioblastoma.

The prognosis of brain cancers such as glioblastoma remains poor despite numerous advancements in the field of neuro-oncology. The presence of the blood brain barrier (BBB) along with the highly invasive and aggressive nature of glioblastoma presents a difficult challenge for developing effective therapies. Temozolomide (TMZ) is a first line agent used in the clinic for glioblastoma and it has been useful in increasing patient survival rates. However, TMZ suffers from issues related to its pharmacokinetics, such as a short plasma half-life (2 h), is subjected to P-gp efflux, and has limited extravasation from blood to brain (∼20%). It has been postulated that reducing its efflux and increasing glioblastoma tissue exposure to TMZ could prove useful in treating glioblastoma and preventing tumour recurrence. Herein, ultra-small, large pore silica nanoparticles (USLP) have been loaded with TMZ, surface PEGlyated to reduce efflux and decorated with the cascade targeting protein lactoferrin for efficient uptake across the BBB and into glioblastoma. Our results demonstrate that USLP improves permeability of BBB in vitro as evidenced using a transwell model which mimics endothelial tight junctions with permeation being enhanced using PEGylated particles. Data from TMZ loaded USLP in vitro transwell BBB model also suggests that the USLP formulations can significantly reduce the efflux ratio of TMZ. In vitro apoptosis studies on glioblastoma cell lines U87 and GL261 were conducted which showed an improvement in TMZ induced glioblastoma apoptosis with USLP formulations compared to pure TMZ. Finally, a proof-of-concept preclinical mouse study demonstrated that when given intravenously at 50 mg/kg, USLP particles showed accumulation in the brain within a few hours without any obvious pathophysiological changes in vital organs as assessed via histology. Overall, the data suggests our innovative delivery system is efficient in extravasation from blood and permeating the BBB and has potential to improve efficacy of TMZ in glioblastoma therapy.