Synergistic Nanomedicine Delivering Topoisomerase I Toxin (SN-38) and Inhibitors of Polynucleotide Kinase 3'-Phosphatase (PNKP) for Enhanced Treatment of Colorectal Cancer.

Inhibitors of a DNA repair enzyme known as polynucleotide kinase 3'-phosphatase (PNKP) are expected to show synergistic cytotoxicity in combination with topoisomerase I (TOP1) inhibitors in cancer. In this study, the synergistic cytotoxicity of a novel inhibitor of PNKP, i.e., A83B4C63, with a potent TOP1 inhibitor, i.e., SN-38, against colorectal cancer cells was investigated. Polymeric micelles (PMs) for preferred tumor delivery of A83B4C63, developed through physical encapsulation of this compound in methoxy poly(ethylene oxide)-poly(α-benzyl carboxylate-ε-caprolactone) (mPEO-b-PBCL) micelles, were combined with SN-38 in free or PM form. The PM form of SN-38 was prepared through chemical conjugation of SN-38 to the functional end group of mPEO-b-PBCL and further assembly of mPEO-b-PBCL-SN-38 in water. Moreover, mixed micelles composed of mPEO-b-PBCL and mPEO-b-PBCL-SN-38 were used to co-load A83B4C63 and SN-38 in the same nanoformulation. The loading content (% w/w) of the SN-38 and A83B4C63 to mPEO-b-PBCL in the co-loaded formulation was 7.91 ± 0.66 and 16.13 ± 0.11% (w/w), respectively, compared to 15.67 ± 0.34 (% w/w) and 23.06 ± 0.63 (% w/w) for mPEO-b-PBCL micelles loading individual drugs. Notably, the average diameter of PMs co-encapsulating both SN-38 and A83B4C63 was larger than that of PMs encapsulating either of these compounds alone but still lower than 60 nm. The release of A83B4C63 from PMs co-encapsulating both drugs was 76.36 ± 1.41% within 24 h, which was significantly higher than that of A83B4C63-encapsulated micelles (42.70 ± 0.72%). In contrast, the release of SN-38 from PMs co-encapsulating both drugs was 44.15 ± 2.61% at 24 h, which was significantly lower than that of SN-38-conjugated PMs (74.16 ± 3.65%). Cytotoxicity evaluations by the MTS assay as analyzed by the Combenefit software suggested a clear synergy between PM/A83B4C63 (at a concentration range of 10-40 µM) and free SN-38 (at a concentration range of 0.001-1 µM). The synergistic cytotoxic concentration range for SN-38 was narrowed down to 0.1-1 or 0.01-1 µM when combined with PM/A83B4C63 at 10 or 20-40 µM, respectively. In general, PMs co-encapsulating A83B4C63 and SN-38 at drug concentrations within the synergistic range (10 µM for A83B4C63 and 0.05-1 µM for SN-38) showed slightly less enhancement of SN-38 anticancer activity than a combination of individual micelles, i.e., A83B4C63 PMs + SN-38 PMs at the same molar concentrations. This was attributed to the slower release of SN-38 from the SN-38 and A83B4C63 co-encapsulated PMs compared to PMs only encapsulating SN-38. Cotreatment of cells with TOP1 inhibitors and A83B4C63 formulation enhanced the expression level of γ-HA2X, cleaved PARP, caspase-3, and caspase-7 in most cases. This trend was more consistent and notable for PMs co-encapsulating both A83B4C63 and SN-38. The overall result from the study shows a synergy between PMs of SN-38 and A83B4C63 as a mixture of two PMs for individual drugs or PMs co-encapsulating both drugs.

Case Report: Ocular Manifestation of Mantle Cell Lymphoma.

SIGNIFICANCE: Mantle cell lymphoma (MCL) is a rare lymphoma that can present even more rarely in the orbit. Diagnosis, differentiation, and systemic treatment with the help of an oncologist are necessary for improved prognosis. Eye care providers must be vigilant when addressing ocular findings to determine next steps. PURPOSE: We present a case of presumed orbital fat prolapse confirmed as MCL found on routine eye examination. CASE REPORT: A 72-year-old White man presented for an annual comprehensive eye examination and was found to have conjunctival elevation in the superior and inferior fornices bilaterally. The patient had stable lymphadenopathy on positron emission tomography/computed tomography imaging 1 week before presentation. Coupled with the patient's recent diagnosis of systemic MCL, there was high suspicion that the conjunctival lesions were malignant. Biopsy of the conjunctival lesion confirmed MCL. A reevaluation of the previous imaging with a neuroradiologist confirmed the presence of orbital lesions consistent with MCL. The patient responded to treatment with low-dose focal radiation therapy. CONCLUSIONS: Primary eye care providers should be aware of limitations of orbital imaging during routine positron emission tomography and computed tomography scans in those with MCL, and consultation with neuroradiology for image review may be useful if the clinical findings are suspicious.

Family physicians' preferences for education to support family caregivers: a sequential mixed methods study.

BACKGROUND: One in four Canadians is a family caregiver. Family caregivers (carers, care-partners) are relatives or chosen family, friends, or neighbors who provide 75 to 90% of the care for people with physical or mental illness, disabilities, or frailty living in community homes and assist with 15 to 30% of the care in congregate care. However, a recent (2022) Statistics Canada population health study reports 44% of family caregivers are distressed. Family physicians and primary care teams are well-positioned to support family caregivers; yet, family caregiver needs assessments tend to be ad hoc and their most common needs remain unmet. Research recommends training healthcare professionals to enhance their knowledge and skills to support family caregivers. METHODS: The objective of this sequential mixed methods research, a survey followed by qualitative interviews, was to explore family physicians' desire and preferences for education about supporting family caregivers. 85 family physicians completed the online survey and eight took part in the interviews. Results from the survey and interviews were compared, contrasted, and interpreted together. RESULTS: Primary care physicians expressed a desire to be better equipped to assess and support FCGs' needs. Even though most physicians (61%) were very/confident about addressing family caregivers' needs, 72% were highly/interested in education to support family caregivers of their patients. Topics with the most interest were assessing family caregivers needs in an organized way, assisting family caregivers to access resources, and address system and practice barriers to support family caregivers. The overarching theme running through the interviews was physicians hope for education to help change the patient-focused culture to inclusion of FCGs. The three themes reflect physicians' conviction about including family caregivers in patient care: We need to take care of their caregivers, Practice and system barriers thwart including family caregivers, and Practical education might help. CONCLUSIONS: This study of family physicians' preferences for education to support family caregivers will inform the development of education about supporting family caregivers for family physicians and trainees.

Design and optimization of metformin hydrophobic ion pairs for efficient encapsulation in polymeric drug carriers.

Loading small molecular weight hydrophilic drugs into polymeric carriers is a challenging task. Metformin hydrochloride (MET) is a highly soluble oral antidiabetic drug of small size and high cationic charge. Hydrophobic ion pairing (HIP) is an approach for reversible modulation of solubility and hydrophilicity of water-soluble drugs via complexation with oppositely charged molecules. Herein, we prepared MET ion pairs and carefully studied and characterized MET interaction with different ligands, with the aim of increasing MET lipophilicity and loading efficiency. HIP was successful using three hydrophilic anionic ligands; sodium dodecyl sulphate (SDS) Carbopol (CB) and tannic acid (TA). Electrostatic interaction and hydrogen bonding drove the complexation per spectroscopic and thermal studies. Complexation efficiency depended on ligand type and charge ratio. While complexes had varying interaction strengths, the excessive stability of TA/MET resulted in unfavorable poor MET dissociation. Notably, HIP imparted a 450 and tenfold lipophilicity increase for SDS/MET and CB/MET, respectively. The latter showed favorable controlled, yet complete release of MET at pH 6.8 and was loaded into alginate beads. Complex bulkiness and decreased lipophilicity resulted in a dramatic 88% increase of MET loading, demonstrating the success of HIP as a simple, efficient and applicable approach for modulating drug's properties.

Appraisal for the Potential of Viral and Nonviral Vectors in Gene Therapy: A Review.

Over the past few decades, gene therapy has gained immense importance in medical research as a promising treatment strategy for diseases such as cancer, AIDS, Alzheimer's disease, and many genetic disorders. When a gene needs to be delivered to a target cell inside the human body, it has to pass a large number of barriers through the extracellular and intracellular environment. This is why the delivery of naked genes and nucleic acids is highly unfavorable, and gene delivery requires suitable vectors that can carry the gene cargo to the target site and protect it from biological degradation. To date, medical research has come up with two types of gene delivery vectors, which are viral and nonviral vectors. The ability of viruses to protect transgenes from biological degradation and their capability to efficiently cross cellular barriers have allowed gene therapy research to develop new approaches utilizing viruses and their different genomes as vectors for gene delivery. Although viral vectors are very efficient, science has also come up with numerous nonviral systems based on cationic lipids, cationic polymers, and inorganic particles that provide sustainable gene expression without triggering unwanted inflammatory and immune reactions, and that are considered nontoxic. In this review, we discuss in detail the latest data available on all viral and nonviral vectors used in gene delivery. The mechanisms of viral and nonviral vector-based gene delivery are presented, and the advantages and disadvantages of all types of vectors are also given.