Self-assembled multifunctional nanotheranostics against circulating tumor clusters in metastatic breast cancer.

Circulating tumor clusters (CTC) disseminating from the primary tumor are responsible for secondary tumor formation where the conventional treatments such as chemotherapy and radiotherapy does not prevent the metastasis at locally advanced stage of breast cancer. In this study, a smart nanotheranostic system has been developed to track and eliminate the CTCs before it can colonize at a new site, which would reduce metastatic progression and increase the five-year survival rate of the breast cancer patients. Targeted multiresponsive (magnetic hyperthermia and pH) nanomicelles incorporated with NIR fluorescent superparamagnetic iron oxide nanoparticles were developed based on self-assembly for dual modal imaging and dual toxicity for spontaneous killing of CTCs in blood stream. A heterogenous tumor clusters model was developed to mimic the CTCs isolated from breast cancer patients. The nanotheranostic system was further evaluated for the targeting property, drug release kinetics, hyperthermia and cytotoxicity against developed CTC model in vitro. In vivo model in BALB/c mice equivalent to stage III and IV human metastatic breast cancer was developed to evaluate the biodistribution and therapeutic efficacy of micellar nanotheranostic system. Reduced CTCs in blood stream and low distant organ metastasis after treatment with the nanotheranostic system demonstrates its potential to capture and kill the CTCs that minimize the secondary tumor formation at distant sites.

Facile fabrication of Bi-layered perfusable hydrogel tubes as biomimetic 3D arterial construct.

Small-diameter arterial conduits with native physiological and biological equivalence continues to be a constant global demand posing critical challenges in fabrication. Advent of various strategies towards mimicking the structural hierarchy of a native blood vessel, often involve complex instrumentation and template-assistance with post-processing complications eventually compromising structural fidelity. In the present research, we report a template-free, facile strategy- '3D wet writing' by peripheral-core differential ionic gelation to fabricate perfusable customizable constructs of any dimension, thickness and length in <5 mins. Dual-crosslinking using di-diol complexation of borax with Alginate- poly (vinyl alcohol) was performed to enhance the stability of fabricated bi-layered tubular constructs (BLT). These fabricated BLTs demonstrated non-linear mechanical characteristics of native blood vessels in withstanding physiological (120/80 mmHg) hemodynamic loading conditions with cyclic strain (5.82 ± 0.88%). The BLTs also ensured adequate longitudinal (0.176 ± 0.03 MPa) & circumferential (0.29 ± 0.012 MPa) tensile strength and burst pressure strength of 353.875 ± 22.69 mmHg. Hemocompatible characteristics of BLT were clearly evident with lower hemolytic index (0.21 ± 0.03%) and maintenance of erythrocyte structural integrity under dynamic conditions. Further, non-thrombogenic and non-inflammatory characteristics of BLTs were confirmed by in-activated platelets and monocytes under dynamic conditions. The developed wet-writing technique exhibited facile integration of layer-specific cells concurrently with the BLT fabrication. The spatial cell-specific expressions of smooth muscle (α-SMA) and endothelial (CD-31) cells in BLT were comparable to native hierarchical cellular organization with the multi-layered medial and mono-layered intimal layers. Further,ex-vivodynamic studies on anastomotic interface between BLT and rat abdominal aorta clearly evidenced the functional efficacy of fabricated BLTs as physiologically relevant small-diameter vascular construct.

Reverse engineering of an anatomically equivalent nerve conduit.

Reconstruction of peripheral nervous tissue remains challenging in critical-sized defects due to the lack of Büngner bands from the proximal to the distal nerve ends. Conventional nerve guides fail to bridge the large-sized defect owing to the formation of a thin fibrin cable. Hence, in the present study, an attempt was made to reverse engineer the intricate epi-, peri- and endo-neurial tissues using Fused Deposition Modeling based 3D printing. Bovine serum albumin protein nanoflowers (NF) exhibiting Viburnum opulus 'Roseum' morphology were ingrained into 3D printed constructs without affecting its secondary structure to enhance the axonal guidance from proximal to distal ends of denuded nerve ends. Scanning electron micrographs confirmed the uniform distribution of protein NF in 3D printed constructs. The PC-12 cells cultured on protein ingrained 3D printed scaffolds demonstrated cytocompatibility, improved cell adhesion and extended neuronal projections with significantly higher intensities of NF-200 and tubulin expressions. Further suture-free fixation designed in the current 3D printed construct aids facile implantation of printed conduits to the transected nerve ends. Hence the protein ingrained 3D printed construct would be a promising substitute to treat longer peripheral nerve defects as its structural equivalence of endo- and perineurial organization along with the ingrained protein NF promote the neuronal extension towards the distal ends by minimizing axonal dispersion.

Surface modified NIR magnetic nanoprobes for theranostic applications.

Objectives: Near-Infrared based imaging modalities integrated with thermotherapy can facilitate detection of cancer at early stages and mediate high-resolution image-guided hyperthermia. In this work, fluorescent iron oxide nanoparticles (FIO) have been developed possessing deep tissue penetrable NIR imaging and site-specific magnetic hyperthermia characteristics for the elimination of cancer cells.Methods: One-pot synthesis of amine-functionalized superparamagnetic iron oxide nanoparticles (HIO) were achieved using ethylenediamine (EDA) facilitated conjugation of indocyanine green (ICG) mediated by electrostatic interactions.Results: EDA acts as a capping and reducing agent to direct the structural growth of hydrophilic Fe3O4 nanocrystals with high saturation magnetization, specific absorption rate, and T2 value of 118 emu/g, 329.8 ± 5.96 W/g, and 40.17 mM-1s-1, respectively. Here, Fe2+/Fe3+ of two was maintained to achieve magnetite nanocrystals contradictory to the gold standard ratio of 0.5 without additives for nucleation and growth. Developed FIO showed excellent cytocompatibility even at higher concentrations and on subjecting to magnetic hyperthermia reduced its survival percentage. FIO biodistribution in mice showed enhanced half-life than free ICG with preferential localization in the brain and liver.Conclusion: Developed FIO using a facile technique is a potential clinical alternative for cellular tracking, imaging, and hyperthermia.

Marigold-like tyrosinase-embedded nanostructures-a nano-in-micro system.

Marigold-like tyrosinase-entrenched nanostructures were developed by a facile method using a metal cofactor to overcome the limitations of conventional enzyme immobilization techniques. The protein-copper complex promotes the hierarchical self-assembly of nanopetals into marigold-like microstructures through a sequential germination process. Nanopetals, which originated from bead-like tiny projections, showed budding over the surface and promoted the anisotropic growth of copper phosphate nanocrystals upon co-ordination with the active functional groups in protein. This organic-inorganic hybrid showed excellent re-usability, comparable catalytic efficiency, faster reaction rate, improved storage, and thermal stability without affecting the enzyme activity.

Additive manufacturing of biodegradable porous orthopaedic screw.

Advent of additive manufacturing in biomedical field has nurtured fabrication of complex, customizable and reproducible orthopaedic implants. Layer-by-layer deposition of biodegradable polymer employed in development of porous orthopaedic screws promises gradual dissolution and complete metabolic resorption thereby overcoming the limitations of conventional metallic screws. In the present study, screws with different pore sizes (916 × 918 µm to 254 × 146 µm) were 3D printed at 200 µm layer height by varying printing parameters such as print speed, fill density and travel speed to augment the bone ingrowth. Micro-CT analysis and scanning electron micrographs of screws with 45% fill density confirmed porous interconnections (40.1%) and optimal pore size (259 × 207 × 200 µm) without compromising the mechanical strength (24.58 ± 1.36 MPa). Due to the open pore structure, the 3D printed screws showed increased weight gain due to the deposition of calcium when incubated in simulated body fluid. Osteoblast-like cells attached on screw and infiltrated into the pores over 14 days of in vitro culture. Further, the screws also supported greater human mesenchymal stem cell adhesion, proliferation and mineralized matrix synthesis over a period of 21 days in vitro culture as compared to non-porous screws. These porous screws showed significantly increased vascularization in a rat subcutaneous implantation as compared to control screws. Porous screws produced by additive manufacturing may promote better osteointegration due to enhanced mineralization and vascularization.

Clinical complications of biodegradable screws for ligament injuries.

Anterior cruciate ligament (ACL) plays a crucial role stabilizing the knee joint while connecting tibia to femur. Lack of proper treatment of injured ACL can lead to meniscus tear and osteoarthritis. Interference screws secure the graft tissue for superior integration of graft on host tissue during autograft fixation. Metal interference screws come with various disadvantages like mechanical load mismatch, graft laceration, secondary surgical removal and hindrance during MRI and CT post-operative scan. Though biodegradable polymeric screws provide various advantages their clinical outcomes reveal unprecedented complications for long term use of such screws. This review highlights polymer and composite screw currently available for surgical fixations and associated adverse reactions with the proposed mechanism for tunnel enlargement, effusion, osteolysis in ligament repairs. The need for suitable material engineering for development of orthopedic screws for successful rigid fixation has been highlighted in this review.

ECM-Mimetic Multiresponsive Nanobullets Targeted Against Metastasizing Circulating Tumor Clusters in Breast Cancer.

Targeting smaller populations of circulating tumor clusters (CTC) with tumor-initiating and colonization potentials at distant sites in circulation remains a challenge as clusters possess both epithelial and mesenchymal characteristics. Bullet shaped ellipsoidal nanostructures of size 600 ± 11.3 nm (major axis) and 281.9 ± 5.3 nm (minor axis) with 2.2 aspect ratio were self-assembled using inorganic and organic GRAS biomaterials to preferentially target tumor-causing CTCs. Negatively-charged chondroitin sulfate in presence of gelatin guides unidirectional growth of calcium carbonate mesocrystals to form nanobullets, mediates CD44 targeting of CTCs. Switchable multi-responsive drug release profiles (temperature and pH) were recorded for nanobullets promoting spontaneous and efficient cell-killing. CD44 and E-cadherin overexpressing 'seeding' cell clusters of 170 ± 22 µm were developed as in vitro CTC model. pH responsive release of Dox into lysosome stimulates calcium influx resulting in cell death. CD44-blocked CTCs showed significantly reduced internalization when compared to CD44-expressing CTCs thereby confirming CD44 specific internalization of nanobullets. Significantly retarded expansion of clusters when shifted to cell adhesive surfaces depicts the potential of nanobullets against colonization of CTCs. Hence, newer insights on developed anisotropic ECM-mimetic nanohybrids would enhance targeted capture of tumor-initiating clusters in systemic circulation that would potentially reduce the progression of tumor in breast cancer patients.

Nanohybrids - cancer theranostics for tiny tumor clusters.

Breakthroughs in clinical translation of cancer nanomedicine revolutionized smart theranostics approaches by addressing cancer heterogeneity using multifunctional treatment strategies. Geometrical anisotropy, supramolecular nanoarchitecture, and multiplex functionalities exemplified by various techniques incites the development of integrated multi-modal drug delivery systems for circulating tumor clusters (CTC). Average survival rate of the patients with locally advanced tumor demands the intelligent theranostic system to control the primary progression, invasion and extravasation of CTCs. However, rapid elimination of these highly aggressive and metastatic clusters of tumor cells disseminated in blood, prior to soiling at new distant sites, would increase the lifespan of the patients. This review provides insight on RSSR (Retention, Stealth, Sticky, and Release) strategy for engineering smart hybrid nanostructures to target CTC and thereby terminate the metastatic cascade before formation of secondary niches.

Surface topography of polylactic acid nanofibrous mats: influence on blood compatibility.

Fabricating nanofibrous scaffolds with robust blood compatibility remains an unmet challenge for cardiovascular applications since anti-thrombogenic surface coatings did not withstand physiological shear force. Hence, the present study envisages the influence of smooth and porous topographies of poly(lactic acid) (PLA) nanofibers on hemocompatibility as it could offer time-independent blood compatibility. Further, recent studies have evolved to integrate various contrasting agents for augmenting the prognostic properties of tissue engineered scaffolds; an attempt was also made to synthesize Curcumin-superparamagnetic iron oxide nanoparticle complex (Cur-SPION) as a contrasting agent and impregnated into PLA nanofibers for evaluating the blood compatibility. Herein, electrospun nanofibers of PLA with different topographies (smooth and porous) were fabricated and characterized for surface morphology, zeta potential, fluorescence, and crystallinity. The scaffolds with smooth, porous and rough surface topographies were thoroughly investigated for its hemocompatibility by evaluating hemolysis percentage, platelet adhesion, in vitro kinetic clotting time, serum protein adsorption, plasma recalcification time (PRT), capture and release of erythrocytes. Although the nanofibers of all three groups showed acceptable hemolytic percentage (HP < 5%), the adhered RBCs on Cur-SPION based fibers undergo morphological transformation from biconcave discocytes to echinocytes with cube-like protrusions. On the contrary, no morphological changes were observed in RBCs cultured on smooth and porous nanofibers. Porous fibers exhibited excellent anti-thrombogenic property and adhered lesser platelets and maintained the discoidal morphology of native platelets. Cur-SPION integrated PLA nanofibers showed inactivated platelets with anti-thrombogenic activity compared to smooth nanofibers. In conclusion, PLA nanofibers porous topography did not affect the RBC membrane integrity and maintained discoidal morphology of platelets with superior anti-thrombogenic activity. However, smooth and Cur-SPION integrated PLA nanofibers were found to activate the platelets and deform the RBC membrane integrity, respectively. Hence, the nanofibers with porous structures provide an ideal topography for time-independent hemocompatibility.

Responsive Nanomicellar Theranostic Cages for Metastatic Breast Cancer.

Precluding the progression of metastasis with early diagnosis of triple-negative breast cancer remains challenging due to lack of targeting specificity with poor diagnostic potential. Herein, an amphipathic chitosan-based targeted nanomicellar theranostics (30-45 nm) comprising doxorubicin-superparamagnetic iron oxide nanoparticles complexes (89.23%) with lower critical micelle concentration (0.1 µg/mL) were developed. Micelles exhibit concentration-based contrast enhancement in MRI (r2 6.27 mM-1 s-1) and hyperthermia rather than thermal-ablation. This theranostics delivers doxorubicin under alternating magnetic field (480 kHz) and at endosomal pH (pH 5.2) while showing stability at pH 7.4. Anti-αvß3 integrin antibody conjugation onto PEGylated micelles (62.3%) enhances micellar internalization into drug-resistant MDA-MB-231 after 1 h and magnetizes the cells after 6 h over that with nonconjugated micelles. Immigration of MDA-MB-231 and 4T1 cells retards after 24 h, while significant reduction of mitochondrial membrane potential is observed under hyperthermia. Intratumoral administration of nanomicelles in 4T1 orthotopic spontaneous metastasis model demonstrated antitumor and fibrosis mediated caging effect with simultaneous enhancement of MRI-T2 contrast.

Non-small cell lung carcinoma metastasis to the anus.

A 70-year-old man presenting with a lung mass was investigated and treated with pneumonectomy for adenocarcinoma of the lung. He re-presented 3 months later with a large perianal abscess and mass. Subsequent investigations and biopsies showed disseminated metastases from the lung primary. Immunohistochemical staining confirmed the nature of the anal metastasis from the lung adenocarcinoma. Lung cancer is notorious for metastases, hence it is important to be aware of the uncommon modes of spread, which will help obtain early diagnosis and optimise treatment.

Low documentation of postoperative adhesions on consent forms for laparotomy.

AIM: To assess the documentation of postoperative adhesions as a potential complication of laparotomy on consent forms. METHOD: Retrospective study of hospital notes of 102 adult patients that underwent laparotomy over a two year period. RESULTS: Intraperitoneal adhesions were documented as a postoperative risk on 10 consent forms (9.8%) only. CONCLUSION: The results imply that most patients were not informed of this common postoperative complication and this may have medicolegal and risk management implications.