X-RAY AND MORPHOLOGICAL PARALLELS OF THE OSTEOREGENERATIVE PROCESS AFTER USING THE AGENT BASED ON ION LANTHANIDE ETIDRONATE
Akhtyamov I.F., Zhitlova E.A., Tsyplakov D.E., Boychuk S.V., Shakirova F.V., Korobeynikova D.A.
Kazan State Medical University, Kazan State Academy of Veterinary Medicine, Kazan, Russia
Objective – to study the effect of the agent based on ion lanthanide etidronate and calcium on the process of osteoregeneration in the experimental model of the tibial defect.
Methods. The experiment included 36 rabbits with the experimental tibial damages and subsequent introduction (on the days 3 and 5) of the agent based on ion lanthanide etidronate and calcium with the dosage of 0.2 ml in the main group (n = 18) and without it in the comparison group (n = 18). The roentgen metric and morphological analyzes of the bone tissues, which filled the perforative hole, were performed on weeks 1, 4 and 8 of the experiment. A morphometric method was used in order to quantify the areas of the studied structures. A qualitative assessment of osteoblastic activity was carried out using the cell line MC3T3-E1, Subclone 4 (ATCC® CRL-2593 ™) in order to determine the mechanism of action of the drug.
Results. The studied agent stimulated the healing process of the bone defect already on the day 7 of the experiment that consisted in a decrease of the area of the perforative hole and the volume of leukocyte-necrotic masses. On the fourth week, it caused the closure of the defect by the membrane reticulated bone. At the end of the experiment, in the area of experimentally induced of trauma, the formed lamellar bone could be visualized. The authors found that the tested compound induced the osteoblastic cell activity.
Conclusion. The use of the drug based on lanthanide etidronate and calcium is effective in the early stages of healing of small bone defects.
Key words: defects of bone tissue; reparative osteoregeneration; stimulation
Closure of defects and damages of bone tissue presents the quite longand multi-staged process. The search for osteogenesis-stimulating substances is
the important task in the modern traumatology and orthopedics. This complex
problem has not been solved with significant progress in use of osteoinductors
and osteoconductors for recovery of bone defects [1-4]. Complex compounds
including some mineral components (such as organic stimulators of osteoblast
function) are the perspective measures for bone reparation activation. In this
regard, one should mention a new patented agent of the group of nitrogen-free bisphosphonates
(etidronate) including lanthanide-ions and calcium ions [5]. The etidronate is
the disodium salt of 1-hydroxyethane 1,1-diphosphonic acid, which is the
derivative of etidronic acid.
Etidronic acid (H4L) falls into the group of bisphosphonates and is used
in medicine for prevention of excessive calcium discharge from the bones and
pathologic calcification in soft tissues. Owing to high similarity with
phosphates after addition of the complexes of lanthanide ions to
hydroxyapatites forming the basis of bone tissue, they closely bind to the
minerals and do not influence on the structure of hydroxyapatites. Lanthanides
suppress the development of cells (osteoclasts) responsible for bone tissue
resorption. This ability to imitate the functions of calcium ions allows
modelling their behavior by means of lanthanide ions, as well as using lanthanides
as the components for treating the bone tissue diseases.
It is considered that gadolinium (III) is a “paramagnetic probe”, which
models the behavior of calcium in the biosystems in absence and in presence of
etidronic acid regulating the calcium metabolism. It is important to match the
behavior of these ions and identification of similarity and differences in chemical
quality (stoichiometry and stability) of complex formation with etidronic acid.
The unofficial name of the drug is Inrok.
The primary publications showed the potential ability to influence on
the reparative processes in bone tissue [6, 7].
The objective of the study – to study the effect of the agent based on ion lanthanide etidronate and
calcium on the process of osteoregeneration in the experimental model of the
tibial defect.
MATERIALS AND METHODS
The experimental project was the agent with the following chemical
composition and the ratio of the ingredients:
1. Etidronic acid monohydrate – 1.8
2. Calcium chloride dihydrate – 1.44
3. Gadolinium (III) nitrate hexahydrate – 0.30
4. Dysprosium (III) chloride hexahydrate – 0.038
5. Water for injections
6. Solution pH 7.3-7.8.
Description. The agent is the
water suspension of white color with pearl shade.
The study included 36 rabbits (age of 6-10 months, body weight of
2,500-2,800 g). The experiment included the animals, which were kept in the
conditions of the vivarium. The animal management and care corresponded to the
requirements of GOST ISO 10993 (R). The reparative osteogenesis was estimated
in the experimental model of a non-penetrating defect in the medial surface of
the proximal tibial bone [8] with use of neuroleptanalgesia (Rometar 2 %:
0.15-0.2 ml/kg; Zoletil 100: 10-15 mg/kg). The surgical approach was made two
cm lower than the femoral-tibial junction. The drill was used for making a hole
in the single cortical layer of 3 mm. The wound was sutured with intermittent
knotted sutures.
The republican ethical committee of Kazan State Medical University gave
the permission for the study (the session protocol No.9, November 25, 2014).
The agent was introduced into the modelled defect of
the tibial bone of the rabbit on the third and the fifth day after surgery. The
dosage was 0.2 ml in the experimental group (n = 18). The comparison group did not receive the agent (n
= 18).
The X-ray images for estimation of time course of changes and degrees of
intensity of the reparative osteogenesis in the defect field were conducted in
the end of the first, the second and the eighth weeks of the experiment using
the device 9LU2*. The exposure time was 0.1 sec. with the distance of 70 cm and
current of 20 mA. At the same time, the morphological analysis of the tissue in
a perforative hole and of the boundaries of the defect was conducted. The
histological material was fixed in 10 % neutral formaline, with further
decalcification with a well-known technique [7, 9], dehydration and addition of
paraffine. The histological sections of 5-7 µm thickness were made with the microtome
Leica SM 2000R with hematoxylin-eosin and picrofuxine (van Gieson) staining. The
morphometric method was used for quantitative estimation of the squares of the
structures [10]. The calculation was in percentage to the general square of a
histological section [11].
The statistical analysis was conducted with SPSS 13.0. The normalcy of
distribution was estimated with Kolmogorov-Smirnov test. Student’s test was
used for comparison of the values in two groups. The variance analysis was used
for comparison of the values in three groups and more. The subsequent
intergroup comparison was conducted with Student’s test with Bonferonni
adjustment. The differences were statistically significant with p < 0.05.
The data was presented as M ± m, where M – mean arithmetic, m – standard error
of mean.
Along
with X-ray and morphometric analyses, the osteoblast activity of the drug was
performed with MC3T3-E1 Subclone 4 (ATCC® CRL-2593™). The control measure was the
solution of melatonin (50 nm/l). The qualitative estimation of the compound was
conducted according to the general protocol with use of the commercial set In
Vitro Osteogenesis Assay Kit (Millipore, USA) (Cat. ECM810). MC3T3-E1 line
cultivation was conducted in the complete cultural media alpha-MEM (Gibco, USA)
up to achievement of cellular confluence with subsequent passaging in 24-basin flat-bottomed
tray (Corning, USA). TC-20 automatic counter was used for calculation of cells
in suspension (BioRad, USA). In vitro examination of osteoblast activity of the
agent was performed with the common techniques using In Vitro Osteogenesis
Assay Kit (Millipore, USA) and the cell line MC3T3-E1 from the American bank of
ATCC cellular cultures. The set and the above-mentioned cell line have been
used for in vitro estimation of osteoblast activity of substances for many
years. Melatonin was in this set and was used by us (according to the protocol)
as the positive control, i.e. the inductor of osteoblast activity in the
examined cell line. Therefore, there were the cell cultures incubated with the
various concentrations of the substance, and the cell cultures incubated with
melatonin (the positive control) and without introduction of any substances
(the negative control).
We
have shown that the osteoblast activity of the compound increased the values of
the positive control within the levels of 500 µm and 1 mM. Moreover, an evident
dose-depending effect was identified (induction of osteoblast activity). The
conclusion was made that one of the possible molecular mechanisms of action of
the studied compound was its ability to increase the activity of osteoblasts in
the injury site.
After
achieving cellular confluence, the complete nutritional media on the basis of Alpha
Minimum Essential Medium was replaced by Osteogenesis Induction Medium. After
six days of cultivation of MC 2T3-E1 cell line, the cultural media was replaced
by Osteogenesis Induction Medium with solution of the examined compound with
levels of 1, 10, 100, 250, 500 and 1,000 µm. After completing six days of
cultivation, the qualitative response to the osteoblast activity was estimated
with alizarin. After completion of incubation, the basins were washed with d
water (4 times), and optic microscopy was conducted.
RESULTS
The
rabbits showed good tolerance to general anesthesia and surgery. Motion activity
restored 30 minutes after surgery. The animals could eat 5 hours later. The
postsurgical wounds healed with primary intention in all cases. Wound
infection, allergic reactions and other complications were not identified.
The
X-ray examination showed the perforative holes in the upper parts of the tibial
bones with smooth and clear borders in both groups (Fig. 1a).
Figure 1. The X-ray image and photomicrography (x400) of the defect in the animal
of the experimental group 7 days after surgery: a) a perforative hole of
the shin bone; b) granulation tissue. The osteoblasts are marked with the
arrows. Hematoxylin and eosine staining.
The
microscopic analysis showed the unfilled defect in the experimental group at
that stage of the experiment (15.9 ± 1.4 %, p = 0.003). Traumatic edema was
absent at that stage, or it was insignificant. The vessels were extended and
full-blooded. The blood clots were organized in the field of the defect.
Granulation hematoma was present in each case at the background of hematoma
organization. The square of granulation tissue was 70.6 ± 1.1 % (p = 0.02), in the
comparison group – 53.6 ± 3.1 % (Fig. 1b). Osteoblasts were visualized along
with new vessels and mesenchymal cell elements. Inflammatory response was only
in individual cases, where insignificant macrophageal infiltration was present.
Insignificant leukocytic necrotic masses were in two cases in the experimental
group: 5.5 ± 0.8 % (p = 0.001). They had the lower square than in the comparison
group (14.6 ± 1.4 %).
In
the comparison group, the square of the unfilled perforative hole was 27.6 ±
2.1 %. Anatomically, the residual events of reactive processes (exudative
inflammation) as consequences of trauma were evident. Infiltration by
polymorphic nuclear leukocytes was present to a greater or lesser degree,
followed by macrophageal infiltration.
In
some cases in the comparison group, some necrotic changes with desolate
cavities of osteocytes and calcification foci appeared. Totally, leukocytic necrotic
masses occupied 14.6 ± 1.4 % of the square of the section. In most cases, the
process of regeneration with proliferation of blood vessels and migration of fibroblasts,
which were between vascular slings, began. Granulation tissue appeared. Its square
was not more than 53.6 ± 3.1 % (the table). One case had the inflammatory
process with extensive leukocytic necrotic masses. The signs of reparation were absent.
Table. The squares of structural components filling up the perforative hole at different time points of the experiment (the percent of total square of histological section, М ± m)
|
7th day |
14th day |
28th day |
56th day |
||||
Comparison group |
Experimental group |
Comparison group |
Experimental group |
Comparison group |
Experimental group |
Comparison group |
Experimental group |
|
Non-filled perforative hole |
27.6 ± 2.1 |
15.9 ± 1.4* |
10.4 ± 0.7 |
1.5 ± 0.7* |
- |
- |
- |
- |
Leukocytic-necrotoc masses and blood clots |
14.6 ± 1.4 |
5.5 ± 0.8* |
2.2 ± 0.6 |
0.6 ± 0.6 |
- |
- |
- |
- |
Granulation tissue |
53.6 ± 3.1 |
70.6 ± 1.1* |
17.2 ± 2.1 |
6.7 ± 1.1* |
1.5 ± 0.3 |
0.4 ± 0.2* |
- |
- |
Connective tissue |
4.1 ± 1.2 |
8.0 ± 0.9 |
48.2 ± 0.6 |
68.0 ± 2.5* |
7.3 ± 1.1 |
3.6 ± 0.6 |
- |
- |
Cartilaginous tissue |
- |
- |
16.1 ± 1.5 |
5.1 ± 1.3* |
4.0 ± 0.9 |
0.6 ± 0.1 |
4.2 ± 0.2 |
0.4 ± 0.2 |
Membrane reticulated bone of beam structure |
- |
- |
6.0 ± 1.0 |
18.2 ± 0.6* |
86.0 ± 1.9 |
92.2 ± 0.9 |
7.1 ± 0.4 |
0.8 ± 0.1 |
Lamellar bone |
- |
- |
- |
- |
1.2 ± 0.3 |
3.2 ± 0.4* |
88.7 ± 0.6 |
98.8 ± 0.2* |
Note: * – statistically significant differences in values between the groups.
In
the end of the second week of the experiment, the square of the perforative
defect decreased 2.65 times in the comparison group. Growth of collagen fibers
and process of osteogenesis began in each case, where granulation tissue
appeared at the previous stage. At the background of collagen homogenization,
the bone rods developed, with loose areolar connective tissue filling the space
between them. Transverse bridges appeared between some bone rods. Proliferating
osteoblasts were found. Connective tissue took the general square of 48.2 ± 0.6
%. Necrotic masses (also in bone tissue) almost resolved.
The
blood vessels grew into the Haversian canals on the edges of the defect. In
some cases, bone formation happened by means of development of cartilaginous
tissue, which was presented by small regions or extensive fields of connective
tissue. The cartilage square was 16.1 ± 1.5 % for this time interval. Two
rabbits had the persistent inflammatory processes with cellular infiltration
and focal tissue necrosis, but their square was not high (2.2 ± 0.6 %). One
case had some necrotic changes in the adjacent periosteal tissues.
At
the same time, the main group showed the decreasing proportion of granulation
tissue and the increasing volume of connective tissue: 6.7 ± 1.1 % (p = 0.004),
68 ± 2.5 % (p < 0.001) correspondingly. Three cases were associated with
formation of rough fibrous tissue, which rods were connected to bone tissue of
the defect’s borders. The square of rough fibrous bone tissue was 18.1 ± 0.6 %
(p < 0.001). The defect had almost closed by that time, and its square was
only 1.5 ± 0.7 % (p < 0.001). Formation of the cartilage was minimal and did
not exceed 5.1 ± 1.3 % (p = 0.001). The inflammatory response was absent or
minimal, with background reparative processes.
The
bone defect of the tibial bone was almost closed in most cases in the end of
the fourth week. The animals of the comparison group had the rough fibrous
bone, with its square of 86.0 ± 1.9 %. The trabecules showed the partial
resorption on the borders of the former hole. Lamellar bone formation began,
but the volume of the bone was still insignificant (1.2 ± 0.3 %). When cartilaginous
tissue formed during the process of the defect healing, its resolution,
calcification and replacement by bone tissue happened. The signs of inflammatory
response were absent. Some cases included the defect closing with presence of
cartilaginous tissues on the borders (without ossification) and immature rough
fibrous tissue bone.
At
that period of observation in the experimental group, the perforative hole was
replaced by the rough fibrous bone (92.2 ± 0.9 %) with diffuse calcification of
the rods. The bone transformed to the lamellar bone 2.66 times more often than
in the comparison group (Fig. 2b). The cartilaginous tissue was minimal (0.6 ± 0.1 %).
Figure 2. The X-ray image and photomicrography (x400) of the defect in the animal
of the main group 28 days after surgery: a) a perforative hole of the shin
bone; b) transformation of cartilaginous tissue into a rough fibrous bone.
Hematoxylin and eosine staining.
TheX-ray examination showed the bone defect with non-uniform wideness of sclerosis
zone (1-2 mm) and local hyperostosis in the animals in both groups. In the
comparison group, the borders of the hole usually had the unsmooth internal
contours. The experimental group showed some signs of periosteal response at
the level of the defect’s boundaries (Fig. 2a).
In
the end of the experiment (the eighth week of observation), most animals of the
comparison group demonstrated the lamellar bone (88.7 % ± 0.6 % of the
section). But some individual cases showed the fragments of rough fibrous bone
(7.1 ± 0.4 %), the regions of resolution of cartilaginous tissue with
ossification events and presence of necrosis foci and destruction of the
cartilage and the bone. Generally, cartilaginous tissue remained only on 4.2 ±
0.2 % of the perforative hole.
The
complete uncomplicated recovery of the bone defect was diagnosed in the
experimental group at that time. The lamellar bone (the square of 98.8 ± 0.2 %,
p < 0.001) appeared at the place of the perforative hole. It had the evolved
system of Haversian canals and restored surrounding periosteal tissues.
The
X-ray examination did not show any complete replacement of the bone defect in
both groups at that time. The contours of the hole were unsmooth, with
non-uniform wideness of sclerosis zone (1.5-3 mm) and local hyperostosis (0.5
mm). Therefore, objective estimation of the X-ray images did not identify any
significant changes between the animals of the experimental and comparison
groups.
CONCLUSION
1. Dosed
administration of the agent with etidronate of lanthanide ions and calcium is
efficient already in early stages of recovery of small bone defects. The feature
of the agent (or its specificity) is the complex influence: 1) decreasing
intensity of inflammation; 2) increasing reparation; 3) influence on
osteogenesis, which is direct in most cases.
2.
The efficiency of this compound can be based on increasing osteoblast activity
of cellular elements in the region of the injury.
3.
Scientific novelty of the studies consists in the fact of the first appearance
of the injectable form of the agent based on etidronate of lanthanide ions and
calcium with osteoinductive properties. The complex approach showed that
introduction of the agent did not cause any acute inflammatory responses in
tissues in the region of introduction. The morphometric (morphological) studies
showed that the first seven days after initiation of the defect in the animals
of the experimental group resulted in formation of granulation tissue with
subsequent formation of reticulofibrous and lamellar bone.
4.
On the basis of the received data of specific activity of the agent containing
the lanthanide ions and calcium in the model of partial bone injury, one may
make a judgment on the possible perspective of its clinical use.
Information about conflict of interests
The study was conducted without sponsorship. The authors declare the absence of any clear and potential conflicts of interests relating to publication of this article.
REFERENCES:
1. Pakht AV, Manizer NM. The
features of bone tissue preparation. Library
by Anatomical Pathologist: scientific practical journal. 2008; 89: 6-11. Russian
(Пахт А.В., Манизер Н.М. Особенности обработки костной ткани //Библиотека патологоанатома: научно-практический журнал. 2008. Вып. 89. С. 6-11)
2. Talashova
IA, Osipova NA, Kononovich NA. The comparative quantitative estimation of the
reparative process during implantation of biocomposite materials into bone
defects. Genius of Orthopedics. 2012; 2: 68. Russian (Талашова И.А., Осипова
Н.А., Кононович Н.А. Сравнительная количественная оценка репаративного процесса
при имплантации биокомпозиционных материалов в костные дефекты //Гений
ортопедии. 2012. № 2. С. 68)
3. Tsyplakov DE, Izosimova AE,
Shakirova FV, Akhtyamov IF, Gatina EB. Morphometric substantiation of osteosynthesis
with implants coated with titanium nitrides and hafnium. Kazan Medical Journal. 2016; 4: 585-591. Russian (Цыплаков Д.Э., Изосимова А.Э., Шакирова Ф.В., Ахтямов И.Ф., Гатина Э.Б. Морфометрическое
обоснование остеосинтеза с использованием имплантатов с покрытием нитридами
титана и гафния //Казанский медицинский журнал.
2016. № 4. С. 585-591)
4. Kabirov
G, Shakirova F, Manirambona JC, Akhtyamov I, Gatina E, Tsiplakov D. Morphological studies of local influence of implants
with coatings based on superhard compounds on bone tissue under conditions of
induced trauma. J. Fac. Vet. Med. Istanbul Univ. 2015;
41(2): 177-184
5. Devyatov
FV, Kholmogortsev EG. A method of bone tissue regeneration in the experiment:
the patent No.2248210С1/No.2003120703/14; 07.07.2003. Russian (Девятов Ф.В., Холмогорцев Е.Г. Способ
регенерации костной ткани в эксперименте: патент № 2248210С1/ № 2003120703/14; 07.07.2003)
6. Zhitlova EA, Shakirova FV. The quantitative staged
estimation of bone regenerate in the region of induced trauma during
introduction of the diphosphate-based agent. Ippology and Veterinary. 2016; 3(21): 43-48. Russian (Житлова
Е.А., Шакирова Ф.В. Количественная этапная оценка костного регенерата в
зоне индуцированной травмы при введении препарата на основе дисфосфатов //Иппология
и ветеринария. 2016. № 3(21). C. 43-48)
7. Zhitlova EA, Tsyplakov DE,
Shakirova FV. The quantitative estimation of the reparative process during
introduction of lantanoid etidronate and calcium-based agent into the bone
defect. Morphology. 2016; 3:
82-83. Russian (Житлова
Е.А., Цыплаков Д.Э., Шакирова Ф.В. Количественная оценка репаративного
процесса при введении в костный дефект препарата на основе этидронатов
лантаноидов и кальция //Морфология. 2016. № 3. С. 82-83)
8. Korzhevskiy
DE. The summary of the foundations of histological technique for physicians and
histological laboratory technicians. St. Petersburg: Krof, 2005. 48 p. Russian (Коржевский Д.Э. Краткое изложение
основ гистологической техники для врачей и лаборантов-гистологов. СПб: Кроф, 2005. 48 с.)
9. Netylko GI, Rumakin VP, Konev
VA. The experimental modelling of the bone defect with sclerotic wall. Genius of Orthopedics. 2014; 3: 72.
Russian
(Нетылько Г.И., Румакин В.П., Конев В.А. Экспериментальное моделирование
костного дефекта со склерозированной стенкой //Гений ортопедии. 2014. № 3. C. 72)
10. Avtandilov
GG. Medical morphometry. M.: Medicine, 1990. 384 p.
Russian ( Автандилов Г.Г. Медицинская
морфометрия. М.: Медицина, 1990.
384 с.)
11. Belyanin
VL, Zyplakov DE. Morphometric analysis. Diagnostics of reactive hyperplasia of lymphatic
vessels. St. Petersburg; Kazan, 1999. P. 56-58. Russian (Белянин В.Л., Цыплаков Д.Э. Морфометрический анализ. Диагностика реактивных гиперплазий лимфатических узлов. СПб.; Казань, 1999. С. 56-58)
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