Chemotherapy Release From Bortezomib-Impregnated Polymethylmethacrylate-Coated Intramedullary Nails: A Novel In Vitro Study for a Local Chemotherapy Delivery Device.

Bortezomib (BAN) is a proteasome inhibitor approved for the treatment of multiple myeloma and lymphoma. Despite its efficacy in various tumor models, systemic administration can result in toxicity to healthy organs. The purpose of this study is to evaluate the elution profile of BAN from PMMA cement for the local treatment of orthopedic tumors. BAN solution (5 mg; 2 mg/mL) was mixed with Simplex cement (40 g, Stryker), followed by injection of cement into an antibiotic cement nail mold (13 mm) to coat a 10 mm titanium femoral nail (DePuy Synthes). Once the cement polymerized, the nail was cut into 2 cm segments for the BAN elution study. There is a sustained release of BAN for up to 28 days. The overall concentration of BAN released at each time point was between 74 and 263 ng/ml, which is compatible with the peak blood concentration of a single intravenous BAN injection. This study demonstrates the feasibility of using PMMA bone cement as a local BAN delivery tool, essential for future studies and treatment targeting multiple myeloma cells.

The Impact of Hypoglossal Nerve Stimulation on Secondary Health Outcomes.

Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep disorder that can increase the risk of hypertension, diabetes, obesity, and cardiovascular diseases. Hypoglossal nerve stimulation (HGNS) is an alternative therapy for OSA in patients who cannot tolerate continuous positive airway pressure. Understanding the impact of HGNS on blood pressure, hemoglobin A1C (A1C), and body mass index (BMI) currently remains limited. Methods: A retrospective review study of HGNS outcomes at a single practice from January 2020 to November 2022 was conducted. Inclusion/exclusion criteria were based on HGNS eligibility and postoperative titration study. Statistical analysis and data management were performed using statistical software, R (v.4.2.1; R Core Team). Paired Student's T test, Fisher's exact test, and McNemar's exact test were utilized for statistical analysis. P values less than .05 were considered statistically significant. Results: Sixty-three patients were included in this study. A significant decrease in mean apnea-hypopnea index was noted following HGNS (mean change -28; P < .0001). Similar significant decreases were also seen in mean arterial pressures (mean change -8.4, P < .0001). There was a significant change in overall antihypertensive medication requirements and in requirements ≥3 medications (P < .0005, P = .03). There was a trend toward reduction in A1C; however, there was no change in BMI or number of diabetes medications taken. Conclusions: Our results reinforce previous findings that HGNS is an effective treatment option for carefully selected patients with OSA. In addition, our findings suggest that HGNS may improve patients' quality of life while minimizing OSA associated morbidity.

Antibiotic cement nails manufactured with threaded rods or cannulated intramedullary nails are better than those made with guidewires and do not debond.

Purpose: The purpose of this study was to comparatively evaluate cement debonding at the time of removal of antibiotic cemented coated nails (ABNs) with cores made with a guidewire ($120), a regular intramedullary nail ($1100) or a threaded rod from a circular frame external fixator set ($60). Methods: A retrospective study was performed on 32 ABNs that had been implanted for long bone infections after intramedullary nailing. All ABNs were manufactured intraoperatively by the treating surgeon using 2 grams of vancomycin and single package of Tobramycin Simplex Cement (Stryker, Kalamazoo, MI). The powder, antibiotics, and polymer were mixed and then injected into an ABN cement mold (Bonesetter Holdings USA). Debonding was assessed at time of removal by the operating surgeon. Rates of cement debonding between the 3 groups were statistically compared. Results: Debonding occurred in 0/12 of the cement nails manufactured with an intramedullary nail, 0/7 threaded rod ABNs, and 6/13 guidewire ABNs. There was a significant difference in the rate of debonding between the 3 groups (P < 0.01). Removal of the remnant cement was accomplished with thin osteotomes, long pituitary rongeurs, or reamers. The canal was visualized using an arthroscope to ensure complete removal of the cement. Conclusion: ABNs fabricated with standard intramedullary nails or threaded rods did not lead to any debonding. Debonding of the cement from the inner core of an antibiotic nail often requires significant effort to remove the remnant cement. Given that threaded rods are often cheaper than guidewires, we recommend that ABNs be fabricated with either threaded rods or interlocking nails, but not guidewires, depending on the level of stability required.

Maternal, placental and fetal response to a non-viral, polymeric nanoparticle gene therapy in nonhuman primates.

Background: Currently, there are no placenta-targeted treatments to alter the in utero environment. Water-soluble polymers have a distinguished record of clinical relevance outside of pregnancy. We have demonstrated the effective delivery of polymer-based nanoparticles containing a non-viral human insulin-like 1 growth factor ( IGF1 ) transgene to correct placental insufficiency in small animal models of fetal growth restriction (FGR). Our goal was to extend these studies to the pregnant nonhuman primate (NHP) and assess maternal, placental and fetal responses to nanoparticle-mediated IGF1 treatment. Methods: Pregnant macaques underwent ultrasound-guided intraplacental injections of nanoparticles ( GFP- or IGF1- expressing plasmid under the control of the trophoblast-specific PLAC1 promoter complexed with a HPMA-DMEAMA co-polymer) at approximately gestational day 100 (term = 165 days). Fetectomy was performed 24 h ( GFP ; n =1), 48 h ( IGF1 ; n = 3) or 10 days ( IGF1 ; n = 3) after nanoparticle delivery. Routine pathological assessment was performed on biopsied maternal tissues, and placental and fetal tissues. Maternal blood was analyzed for complete blood count (CBC), immunomodulatory proteins and growth factors, progesterone (P4) and estradiol (E2). Placental ERK/AKT/mTOR signaling was assessed using western blot and qPCR. Findings: Fluorescent microscopy and in situ hybridization confirmed placental uptake and transgene expression in villous syncytiotrophoblast. No off-target expression was observed in maternal and fetal tissues. Histopathological assessment of the placenta recorded observations not necessarily related to the IGF1 nanoparticle treatment. In maternal blood, CBCs, P4 and E2 remained within the normal range for pregnant macaques across the treatment period. Changes to placental ERK and AKT signaling at 48 h and 10 d after IGF1 nanoparticle treatment indicated an upregulation in placental homeostatic mechanisms to prevent over activity in the normal pregnancy environment. Interpretation: Maternal toxicity profile analysis and lack of adverse reaction to nanoparticle-mediated IGF1 treatment, combined with changes in placental signaling to maintain homeostasis indicates no deleterious impact of treatment. Funding: National Institutes of Health, and Wisconsin National Primate Research Center.