Food Rescue and Delivery Nair, Divya Jayakumar; Grzybowska, Hanna; Rey, David ...
Transportation research record,
01/2016, Letnik:
2548, Številka:
1
Journal Article
Recenzirano
This paper addresses a special case of periodic vehicle routing problem in which each node has a nonnegative supply or demand of a single product that is unpaired. The product collected from a pickup ...node can be delivered to any one node or multiple delivery nodes, and the demand of a delivery node can be met by the product collected from any one node or multiple pickup nodes. This periodic unpaired pickup and delivery vehicle-routing problem is a novel variant of the periodic vehicle routing problem. The objective of the problem was to design the pickup and delivery vehicle routes to meet required service levels of delivery nodes, minimizing the total transportation cost while satisfying certain operational constraints. This problem was driven by food relief operations in Sydney, Australia. The logistics aspect of the approach was to design and execute a vehicle routing problem for a food rescue and delivery network. The specific goals were to develop an integrated linear programming model for this new variant of the periodic vehicle routing problem and to propose an integer programming–based heuristic solution approach to solve the problem introduced in the paper. The heuristic algorithm was tested with small instances created from Cordeau's benchmark instances, and the solution approach was validated against optimal solutions obtained through the exact method before implementation on a food rescue and delivery network. The heuristic approach was found to be comparable with the optimal solution and can solve the real-world scenarios with significantly fewer resources than are used in practice.
Nanoformulation of curcumin, (a low molecular weight hydrophobic drug) was prepared by using dextran sulphate and chitosan. The developed nanoparticles were characterized by Dynamic Light Scattering ...measurements (DLS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD) and Differential Thermal Analysis (DTA). The prepared system showed an average size of 200–220
nm with a zeta potential value of −30
mV and showed ∼74% drug entrapment efficiency.
In vitro drug release studies showed a controlled and pH dependent curcumin release over a period of one week. The cytocompatibility of bare nanoparticles was verified by MTT assay; cellular internalisation of curcumin loaded nanoparticles was confirmed by fluorescent imaging and quantified spectrophotometrically, anticancer activity of curcumin loaded nanoparticles was proved by MTT assay and reconfirmed by apoptosis assay (FACS). The results showed preferential killing of cancer cells compared to normal cells by the curcumin-loaded nanoparticles. Thus the developed curcumin loaded nanoformulation could be a promising candidate in cancer therapy.
Chitosan (CS) is a naturally occurring biopolymer. It has important biological properties such as biocompatibility, antifungal and antibacterial activity, wound healing ability, anticancerous ...property, anticholesteremic properties, and immunoenhancing effect. Recently, CS nanoparticles have been used for biomedical applications. However, due to the limited solubility of CS in water its water-soluble derivatives are preferred for the above said applications. In this work, the nanoparticles of CS and its water-soluble derivatives such as
O-carboxymethyl chitosan (
O-CMC) and
N,O-carboxymethyl chitosan (
N,O-CMC) was synthesized and characterized. In addition, cytotoxicity and antibacterial activity of the prepared nanoparticles was also evaluated for biomedical applications.
Chitosan, a deacetylated derivative of chitin is a commonly studied biomaterial for tissue-engineering applications due to its biocompatibility, biodegradability, low toxicity, antibacterial ...activity, wound healing ability and haemostatic properties. However, chitosan has poor mechanical strength due to which its applications in orthopedics are limited. Hydroxyapatite (HAp) is a natural inorganic component of bone and teeth and has mechanical strength and osteoconductive property. In this work, HAp was deposited on the surface of chitosan hydrogel membranes by a wet chemical synthesis method by alternatively soaking the membranes in CaCl
2 (pH 7.4) and Na
2HPO
4 solutions for different time intervals. These chitosan hydrogel–HAp membranes were characterized using SEM, AFM, EDS, FT-IR and XRD analyses. MTT assay was done to evaluate the biocompatibility of these membranes using MG-63 osteosarcoma cells. The biocompatibility studies suggest that chitosan hydrogel–HAp composite membranes can be useful for tissue-engineering applications.
Chitin is a novel biopolymer and has excellent biological properties such as biodegradation in the human body and biocompatible, bioabsorable, antibacterial and wound healing activities. In this ...work,
α- and
β-chitin membranes were prepared using
α- and
β-chitin hydrogel. The bioactivity studies were carried out using these chitin membranes with the simulated body fluid solution (SBF) for 7, 14 and 21 days. After 7, 14 and 21 days the membranes were characterized using SEM, EDS and FT-IR. The SEM, EDS and FT-IR studies confirmed the formation of calcium phosphate layer on the surface of the both chitin membranes. These results indicate that the prepared chitin membranes were bioactive. Cell adhesion studies were also carried out using MG-63 osteoblast-like cells. The cells were adhered and spread over the membrane after 24
h of incubation. These results indicated that the chitin membranes could be used for tissue-engineering applications.
Alginate is a naturally occurring polymer that has been widely accepted as biodegradable and biocompatible material. Incorporation of nanoceramic will improve the capability of polymeric scaffold for ...tissue regeneration. Hence, in this study we fabricated a nanocomposite scaffold using alginate with nanoTiO₂ needles by lyophilization technique. The prepared nanocomposite scaffold was characterized using SEM, XRD, FTIR and TGA. In addition, swelling, degradation and biomineralization capability of the scaffold were also evaluated. The developed nanocomposite scaffolds showed well controlled swelling and degradation when compared to the control alginate scaffold. Cytocompatibility was assessed using MTT assay and cell attachment studies. Results indicated no sign of toxicity and cells were found to be attached to the pore walls offered by the scaffolds. These results suggested that the developed nanocomposite scaffold possess the prerequisites for tissue engineering application. Hence, alginate/nanoTiO₂ composite scaffold can be used as a better option for tissue regeneration.
An injectable hydrogel system is appealing for irregular contours of bone defects, as it could adapt well to the defect margin, and improved handling properties compared to the conventional scaffolds ...such as autograft, ceramic blocks, etc. Here, in this work, an injectable hydrogel system was developed using whitlockite nanoparticles (WL NPs), adipose-derived extra-cellular matrix (ECM) and oxidized alginate. The prepared ECM from adipose tissue were characterized for nucleic acid content and quantified the glycosaminoglycans and collagen. The prepared hydrogel was characterized by scanning electron microscopy and Fourier transformed infrared spectroscopy. The composite hydrogel containing WL NPs showed an enhanced storage modulus and better shear-thinning property. Endothelial cells migration studies revealed both the ECM protein and WL NPs acted as a chemoattractant for cells. In vitro tube formation assay showed that the addition of WL NPs in the hydrogel provided the angiogenic potential. Further, in vitro osteogenic differentiation exhibited an enhanced alkaline phosphatase expression for the hydrogel containing WL NPs. These studies indicate that the developed injectable hydrogel system can be a good candidate for non-load bearing bone tissue engineering applications.
The chitin/gelatin composite membranes were prepared by mixing of chitin hydrogel with gelatin. The prepared composite membranes were characterized by scanning electron microscopy (SEM), X-ray ...diffraction (XRD), mechanical, swelling, enzymatic degradation and thermal studies. The XRD pattern of the chitin/gelatin composite membranes showed almost the same pattern as α-chitin. The bioactivity studies of these chitin/gelatin membranes were carried out with the simulated body fluid solution (SBF) for 7, 14 and 21 days followed by the characterization with the scanning electron microscopy (SEM) and Energy Dispersive Spectrum (EDS) studies. The SEM and EDS studies confirmed the formation of calcium phosphate layer on the surface of chitin/gelatin membranes. Biocompatibility of the chitin/gelatin membrane was assessed using human MG-63 osteoblast-like cells. After 48
h of incubation, it was found that the cells had attached and completely covered the membrane surface. Thus, the prepared chitin/gelatin membranes are bioactive and are suitable for cell adhesion suggesting that these membranes can be used for tissue-engineering applications.
Alginate is a naturally occurring polymer that has been widely accepted as biodegradable and biocompatible material. Incorporation of nanoceramic will improve the capability of polymeric scaffold for ...tissue regeneration. Hence, in this study we fabricated a nanocomposite scaffold using alginate with nanoTiO
2 needles by lyophilization technique. The prepared nanocomposite scaffold was characterized using SEM, XRD, FTIR and TGA. In addition, swelling, degradation and biomineralization capability of the scaffold were also evaluated. The developed nanocomposite scaffolds showed well controlled swelling and degradation when compared to the control alginate scaffold. Cytocompatibility was assessed using MTT assay and cell attachment studies. Results indicated no sign of toxicity and cells were found to be attached to the pore walls offered by the scaffolds. These results suggested that the developed nanocomposite scaffold possess the prerequisites for tissue engineering application. Hence, alginate/nanoTiO
2 composite scaffold can be used as a better option for tissue regeneration.
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